WO2020213065A1

WO2020213065A1 - Charged particle device, method for emitting charged particle, vacuum forming device, and method for forming vacuum region

Info

Publication number: WO2020213065A1
Application number: PCT/JP2019/016363
Authority: WO
Inventors: 貴行舩津; 龍菅原; 藤本　憲司
Original assignee: 株式会社ニコン
Priority date: 2019-04-16
Filing date: 2019-04-16
Publication date: 2020-10-22

Abstract

The charged particle device is provided with: a vacuum-forming member having a first pipeline connectable to an exhaust device and forming a vacuum region by discharging through the first pipeline a gas in a space in contact with a surface of an object; an emission device for emitting charged particles toward a sample via the vacuum region; and a second pipeline connected to a passing space through which the charged particles pass. At least a portion of a gas in a space around the vacuum region which has a higher atmospheric pressure than the vacuum region is discharged through the first pipeline. The passing space includes at least a part of the vacuum region. The gas is supplied to at least a part of the passing space through the second pipeline.

Description

Charged particle device, irradiation method of charged particles, vacuum forming device, and vacuum region forming method

The present invention relates to, for example, a technical field of a charged particle device for irradiating charged particles, a method for irradiating charged particles, a vacuum forming device for forming a vacuum region, and a method for forming a vacuum region.

The device that irradiates the charged particles irradiates the charged particles through the vacuum region in order to prevent the charged particles from being scattered due to collision with gas molecules. For example, Patent Document 1 describes a scanning electron microscope that forms a local vacuum region by blocking the periphery of an inspection target portion of a test object irradiated with an electron beam, which is an example of charged particles, from the outside air. ing. In such a device (furthermore, any device that forms a vacuum region), it is a problem to appropriately form the vacuum region.

U.S. Patent Application Publication No. 2004/01/44928

According to the first aspect, it has a first conduit that can be connected to an exhaust device, and gas in a space in contact with the surface of an object is discharged through the first conduit to form a vacuum region. A vacuum forming member, an irradiation device that irradiates a sample with charged particles through the vacuum region, and a second conduit that connects to a passage space of the charged particles irradiated from the irradiation device are provided. The pressure is higher than the vacuum region, and at least a part of the gas in the space around the vacuum region is discharged through the first conduit of the vacuum forming member, and the passing space is at least a part of the vacuum region. A charged particle device that supplies a gas to at least a part of the passage space through the second conduit is provided.

According to the second aspect, the first conduit having a first end connected to the exhaust device and a second end connected to the first space in contact with the surface of the object is provided, and the first space is provided. From the vacuum forming member and the irradiation device, which discharges gas through the first conduit to form a vacuum region having a lower pressure than the second space connected to the first space in the first space. It includes an irradiation device that irradiates a sample with charged particles through a vacuum region of the charged particles to be irradiated, and a second conduit that connects to the passage space, and the passage space is at least one of the vacuum regions. A charged particle device is provided that includes a portion and supplies a gas to at least a part of the passage space through the second conduit.

According to the third aspect, by having a first pipeline that can be connected to the exhaust device and discharging gas through the first pipeline in a state of facing a part of the surface of the object. A vacuum forming member capable of forming a vacuum region having a pressure lower than the pressure of the second space in contact with a second portion different from the first portion of the surface in the first space in contact with the first portion of the surface of the object. The passage space includes an irradiation device that irradiates the sample with charged particles through the vacuum region, and a second conduit that connects to the passage space of the charged particles irradiated from the irradiation device. A charged particle device that includes at least a portion of the vacuum region and supplies gas to at least a portion of the passage space via the second conduit is provided.

According to the fourth aspect, it has a first pipeline that can be connected to an exhaust device, and is in contact with the surface of the object with the surface of the object and the end of the first pipeline facing each other. From the vacuum forming member that discharges the gas in the space through the first conduit to form a vacuum region, the irradiation device that irradiates the sample with charged particles through the vacuum region, and the irradiation device. It comprises a second conduit that connects to the passage space of the charged particles to be irradiated, said passage space comprising at least a portion of the vacuum region, and at least the passage space through the second conduit. A charged particle device that supplies a gas to a part is provided.

According to a fifth aspect, it has a first pipeline that can be connected to an exhaust device, and gas in a space in contact with the surface of an object is discharged through the first conduit to form a vacuum region. A vacuum forming member, an irradiation device that irradiates a sample with charged particles through the vacuum region, and a second conduit that connects to a passage space of the charged particles irradiated from the irradiation device are provided. The pressure is higher than the vacuum region, and at least a part of the gas in the space around the vacuum region is discharged through the first conduit of the vacuum forming member, and the passing space is at least a part of the vacuum region. Provided is a charged particle device comprising, and expelling gas from at least a part of the passage space through the second conduit.

According to the sixth aspect, the first conduit is provided with an irradiation device for irradiating the sample with charged particles and a first conduit that can be connected to the exhaust device, and the gas in the space in contact with the surface of the object is passed through the first conduit. A vacuum forming member for forming a vacuum region by discharging through the vacuum region is provided, and the passage space of the charged particles irradiated from the irradiation device includes at least a part of the vacuum region, and a vacuum of at least a part of the passage space is included. A charged particle device for controlling the distance between the object and the vacuum forming member is provided in parallel with controlling the degree.

According to the seventh aspect, the vacuum region is formed by having a first pipeline that can be connected to the exhaust device and discharging the gas in the space in contact with the surface of the object through the first pipeline. A vacuum forming member and an irradiation device for irradiating a sample with charged particles through the vacuum region are provided, and at least a part of the gas in a space around the vacuum region having a pressure higher than that of the vacuum region is a gas. The passage space of the charged particles discharged from the vacuum forming member through the first conduit and irradiated from the irradiation device includes at least a part of the vacuum region, and the vacuum region is used in the first pressure range. A charged particle apparatus is provided that can be set to a first mode in which the vacuum region is used and a second mode in which the vacuum region is used in a second pressure range different from the first pressure range.

According to the eighth aspect, using a vacuum forming member having a first conduit that can be connected to the exhaust device, the gas in the space in contact with the surface of the object is discharged through the first conduit. Forming a vacuum region, discharging at least a part of the gas in the space surrounding the vacuum region at a pressure higher than that of the vacuum region through the first conduit, and at least the vacuum region. Controlling the distance between the object and the vacuum forming member in parallel with irradiating the sample with charged particles that have passed through a passage space including a part and controlling the degree of vacuum of at least a part of the passage space. A method of irradiating charged particles is provided.

According to the ninth aspect, the gas in the space having the first conduit and the first surface connectable to the exhaust device and in contact with the second surface of the object facing the first surface is the first. A vacuum forming member that discharges through the conduit of No. 1 to form a vacuum region, an irradiation device that irradiates a sample with charged particles from an injection port formed on the first surface, and the first surface. A space having a position changing device for changing the positional relationship between the first surface and the second surface based on either one of the posture and the shape of the vacuum region and having a higher pressure than the vacuum region around the vacuum region. At least a part of the gas is discharged through the first conduit of the vacuum forming member, and the passage of the charged particles irradiated from the charged particle irradiator is a charged particle including at least a part of the vacuum region. Equipment is provided.

According to a tenth aspect, a space in contact with a second surface of an object that can face the first surface by using a vacuum forming member having a first conduit and a first surface that can be connected to an exhaust device. The gas is discharged through the first conduit to form a vacuum region, and at least a part of the gas in the space surrounding the vacuum region having a pressure higher than that of the vacuum region is discharged from the first pipe. Discharging through a conduit, irradiating a sample with charged particles from an injection port formed on the first surface, and allowing the charged particles to pass at least a part of the vacuum region. Provided is a method for irradiating a charged particle, which comprises irradiating a sample and changing the positional relationship between the first surface and the second surface based on either the posture and the shape of the first surface. Will be done.

According to the eleventh aspect, the gas in the space having the first conduit and the first surface connectable to the exhaust device and in contact with the second surface of the object facing the first surface is the first. The positional relationship between the first surface and the second surface is determined based on one of the posture and shape of the first surface and the vacuum forming member that discharges through the conduit of the above to form a vacuum region. A vacuum having a changing position changing device, at least a portion of the gas in a space around the vacuum region having a higher pressure than the vacuum region, is discharged through the first conduit of the vacuum forming member. A forming device is provided.

According to a twelfth aspect, a space in contact with a second surface of an object that can face the first surface by using a vacuum forming member having a first conduit and a first surface that can be connected to an exhaust device. The gas is discharged through the first conduit to form a vacuum region, and at least a part of the gas in the space surrounding the vacuum region having a pressure higher than that of the vacuum region is discharged from the first pipe. Formation of a vacuum region including discharging through a pipeline and changing the positional relationship between the first surface and the second surface based on either the posture and the shape of the first surface. A method is provided.

The actions and other gains of the present invention will be clarified from the embodiments described below.

FIG. 1 is a cross-sectional view showing the structure of the scanning electron microscope of the first embodiment. FIG. 2 is a cross-sectional view showing the structure of a beam irradiation device included in the scanning electron microscope of the first embodiment. FIG. 3 is a cross-sectional view showing the structure of the differential exhaust system included in the scanning electron microscope of the first embodiment. FIG. 4 is a perspective view showing the structure of the differential exhaust system of the first embodiment in a state where a plurality of vacuum forming members are separated along the Z-axis direction. FIG. 5 is a plan view showing the shape of the injection surface of the differential exhaust system. FIG. 6 is a cross-sectional view showing how the gas supply device supplies air to at least a part of the beam passing space. FIG. 7 is a cross-sectional view showing how the gas supply device supplies air to at least a part of the beam passing space. FIG. 8 is a cross-sectional view showing how the exhaust device exhausts at least a part of the beam passing space. FIG. 9 is a cross-sectional view showing how the exhaust device exhausts at least a part of the beam passing space. FIG. 10 is a cross-sectional view showing another example of the scanning electron microscope of the first embodiment. FIG. 11 is a cross-sectional view showing the structure of the beam irradiation device included in the scanning electron microscope of the second embodiment. FIG. 12 is a cross-sectional view showing the structure of the beam irradiation device included in the scanning electron microscope of the third embodiment. FIG. 13 is a cross-sectional view showing the structure of the beam irradiation device included in the scanning electron microscope of the fourth embodiment. FIG. 14 is a cross-sectional view showing the structure of the beam irradiation device included in the scanning electron microscope of the fourth embodiment. FIG. 15 is a cross-sectional view showing another example of the structure of a part of the beam irradiation device included in the scanning electron microscope of the fourth embodiment. 16 (a) and 16 (b) are cross-sectional views showing another example of the structure of a part of the beam irradiation device included in the scanning electron microscope of the fourth embodiment. FIG. 17 is a cross-sectional view showing the structure of the beam irradiation device included in the scanning electron microscope of the fifth embodiment. FIG. 18 is a cross-sectional view showing the structure of the scanning electron microscope of the sixth embodiment. FIG. 19 is a cross-sectional view showing the structure of the beam irradiation device included in the scanning electron microscope of the sixth embodiment. FIG. 20 is a cross-sectional view showing the structure of the scanning electron microscope of the seventh embodiment. 21 (a) is a cross-sectional view showing a stage in which the sample is held in a state where the surface of the sample is parallel to both the exit surface and the holding surface, and FIG. 21 (b) is the exit surface and the holding surface. It is sectional drawing which shows the stage which held the sample in a state that the surface of a sample is not parallel to both of. FIG. 22 is a flowchart showing the flow of the first control operation corresponding to the position control operation performed before the stage holds the sample. FIG. 23 is a cross-sectional view showing how one step of the first control operation is being performed. FIG. 24 is a cross-sectional view showing how one step of the first control operation is being performed. FIG. 25 is a cross-sectional view showing how one step of the first control operation is being performed. FIG. 26 is a cross-sectional view showing how one step of the first control operation is being performed. FIG. 27 is a schematic view showing the surface position of the virtual sample estimated from the position of the holding surface of the stage. FIG. 28A is a schematic view showing the positional relationship between the emission surface of the beam irradiation device and the beam irradiation device before moving at least one of the stages, the holding surface of the stage, and the surface of the virtual sample. (B) is a schematic view showing the positional relationship between the emission surface of the beam irradiation device and the stage, the holding surface of the stage, and the surface of the virtual sample after moving at least one of the beam irradiation device and the stage. FIG. 29 is a flowchart showing the flow of the second control operation corresponding to the position control operation performed after the stage holds the sample. FIG. 30 is a cross-sectional view showing how one step of the second control operation is being performed. FIG. 31 (a) is a schematic view showing the positional relationship between the emission surface of the beam irradiator and the beam irradiator before moving at least one of the stages, the holding surface of the stage, and the surface of the sample, and FIG. 31 (b). Is a schematic diagram showing the positional relationship between the exit surface of the beam irradiation device and the holding surface of the stage and the surface of the sample after moving at least one of the beam irradiation device and the stage. FIG. 32 is a cross-sectional view showing the structure of the scanning electron microscope according to the eighth embodiment. FIG. 33 is a cross-sectional view showing the structure of the scanning electron microscope according to the ninth embodiment. FIG. 34 is a cross-sectional view showing the structure of the scanning electron microscope according to the tenth embodiment. Each of FIGS. 35 (a) to 35 (c) is a cross-sectional view showing a positional relationship between a reference member and a measuring device used for associating the first and second measurement coordinate spaces. FIG. 36 is a flowchart showing the flow of the second control operation in the eleventh embodiment. FIG. 37 is a cross-sectional view showing the structure of the scanning electron microscope according to the eleventh embodiment. Each of FIGS. 38 (a) to 38 (c) shows a beam when the second control operation according to the eleventh embodiment is performed in the process of measuring the state of the sample having a surface including three planes intersecting each other. It is sectional drawing which shows the positional relationship between an irradiation apparatus and a sample. FIG. 39 is a cross-sectional view showing the structure of the scanning electron microscope according to the twelfth embodiment. FIG. 40 is a cross-sectional view showing a stage in which the beam irradiation device is moved so that the sample is positioned at a position where the electron beam can be irradiated. FIG. 41 is a cross-sectional view showing a stage in which the optical microscope has moved so that the sample is positioned at a position where the state of the sample can be measured. FIG. 42 is a cross-sectional view showing a stage in which the optical microscope has moved so that the sample is positioned at a position where the state of the sample can be measured. FIG. 43 is a cross-sectional view showing a stage in which the beam irradiator has moved so that the sample is positioned at a position where the electron beam can be irradiated. FIG. 44 is a cross-sectional view showing the structure of the scanning electron microscope according to the thirteenth embodiment. FIG. 45 is a schematic view showing the structure of the pump system of the 14th embodiment. FIG. 46 is a cross-sectional view showing the structure of the scanning electron microscope according to the fifteenth embodiment. FIG. 47 is a cross-sectional view showing how the stage holds the sample in the first modification. FIG. 48 is a cross-sectional view showing how the stage holds the sample in the second modification. FIG. 49 is a cross-sectional view showing a stage in which the optical microscope has moved so that the sample is positioned at a position where the state of the sample can be measured in the second modification. FIG. 50 is a cross-sectional view showing a stage in which the beam irradiator has moved so that the sample is positioned at a position where it can irradiate an electron beam in the second modification. FIG. 51 is a cross-sectional view showing how the stage holds the sample in the third modification. FIG. 52 is a cross-sectional view showing a connection mode between the vacuum pump and the beam irradiator in which transmission of vibration from the vacuum pump to the beam irradiator is suppressed. FIG. 53 is a cross-sectional view showing a connection mode between the vacuum pump and the beam irradiation device in which the transmission of vibration from the vacuum pump to the beam irradiation device is suppressed.

Hereinafter, embodiments of a charged particle device, an irradiation method of charged particles, a vacuum forming device, and a method of forming a vacuum region will be described with reference to the drawings. In the following, a scanning electron microscope (Scanning Electron Microscope) for irradiating a sample W with an electron beam EB via a local vacuum region VSP to acquire information about the sample W (for example, measuring the state of the sample W). An embodiment of a charged particle apparatus and an information acquisition method will be described using an SEM. Sample W is, for example, a semiconductor substrate. However, the sample W may be an object different from the semiconductor substrate. The sample W may be, for example, a disk-shaped substrate having a diameter of about 300 mm and a thickness of about 750 micrometers to 800 micrometers. However, the sample W may be a substrate (or an object) having an arbitrary size and an arbitrary shape. For example, the sample W may be a square substrate for a display such as a liquid crystal display element or a square substrate for a photomask.

Further, in the following description, the positional relationship of various components constituting the scanning electron microscope SEM will be described using the XYZ Cartesian coordinate system defined from the X-axis, the Y-axis, and the Z-axis which are orthogonal to each other. In the following description, for convenience of explanation, each of the X-axis direction and the Y-axis direction is a horizontal direction (that is, a predetermined direction in the horizontal plane), and the Z-axis direction is a vertical direction (that is, a direction orthogonal to the horizontal plane). Yes, in effect, in the vertical direction). Further, it is assumed that the + Z side corresponds to the upper side (that is, the upper side) and the −Z side corresponds to the lower side (that is, the lower side). Further, the −Z direction may be referred to as a gravity direction. The Z-axis direction is also a direction parallel to the optical axis AX of the beam optical system 11 described later included in the scanning electron microscope SEM. Further, the rotation directions (in other words, the inclination direction) around the X-axis, the Y-axis, and the Z-axis are referred to as the θX direction, the θY direction, and the θZ direction, respectively.

(1) Scanning electron microscope SEMa of the first embodiment
First, the scanning electron microscope SEM of the first embodiment (hereinafter, the scanning electron microscope SEM of the first embodiment will be referred to as “scanning electron microscope SEMa”) will be described.

(1-1) Overall Structure of Scanning Electron Microscope SEMa First, the overall structure of the scanning electron microscope SEMa of the first embodiment will be described with reference to FIG. 1. FIG. 1 is a cross-sectional view showing the overall structure of the scanning electron microscope SEMa of the first embodiment. For the sake of simplification of the drawings, FIG. 1 does not show a cross section of some components of the scanning electron microscope SEMa.

As shown in FIG. 1, the scanning electron microscope SEMa includes a beam irradiation device 1, a stage device 2, a support frame 3, a control device 4, a pump system 5, a gas supply device 6, and an exhaust device 7. To be equipped. Further, the pump system 5 includes a vacuum pump 51 and a vacuum pump 52. The scanning electron microscope SEMa may include at least a chamber for accommodating the beam irradiation device 1, the stage device 2, and the support frame 3. Further, the scanning electron microscope SEMa may be provided with an air conditioner connected to this chamber to control at least one of the temperature and humidity of the space in the chamber (particularly, the space around the sample W). At least part of the space in the chamber may be atmospheric pressure space.

The beam irradiating device 1 can emit an electron beam EB downward from the beam irradiating device 1. The beam irradiating device 1 can irradiate the sample W supported by the stage device 2 arranged below the beam irradiating device 1 with the electron beam EB. At this time, the beam irradiation device 1 forms a vacuum region VSP between the beam irradiation device 1 and the surface WSu of the sample W, and then irradiates the sample W with the electron beam EB via the vacuum region VSP. Since the detailed structure of the beam irradiation device 1 will be described later with reference to FIGS. 2 and 3, the description thereof will be omitted here.

The stage device 2 is arranged below the beam irradiation device 1 (that is, on the −Z side). The stage device 2 includes a surface plate 21 and a stage 22. The surface plate 21 is arranged on a support surface SF such as a floor. The stage 22 is arranged on the surface plate 21. A vibration isolator (not shown) is installed between the stage 22 and the surface plate 21 to prevent the vibration of the surface plate 21 from being transmitted to the stage 22.

The stage 22 can hold the sample W. For example, the stage 22 may hold the sample W by vacuum-adsorbing or electrostatically adsorbing the sample W. The stage 22 can hold the sample W on the holding surface (the surface facing the + Z side in the example shown in FIG. 1) HS facing the beam irradiation device 1. The stage 22 can release the held sample W. When the vacuum region VSP is formed between the beam irradiation device 1 and the sample W as described above, the negative pressure caused by the vacuum region VSP acts on the sample W toward the vacuum region VSP (that is, that is). A force that pulls the sample W (toward the beam irradiation device 1) acts. Therefore, in the stage 22, even when the force caused by the formation of the vacuum region VSP acts on the sample W, the sample W is not deformed or the deformation amount of the sample W is equal to or less than the allowable lower limit amount. The sample W is held with an appropriate holding force so as to hold the sample W properly. Further, when the stage 22 properly holds the sample W, the stage 22 is also pulled toward the vacuum region VSP by the negative pressure caused by the vacuum region VSP acting through the sample W. Therefore, the stage 22 is relative to the extent that the stage 22 is not deformed or the amount of deformation of the stage 22 is equal to or less than the allowable lower limit even when the force caused by the formation of the vacuum region VSP is acting on the stage 22. It may have high rigidity.

The stage 22 can move along at least one of the X-axis direction, the Y-axis direction, the Z-axis direction, the θX direction, the θY direction, and the θZ direction while holding the sample W under the control of the control device 4. .. In order to move the stage 22, the stage device 2 includes a stage drive system 23. The stage drive system 23 moves the stage 22 by using, for example, an arbitrary motor (for example, a linear motor or the like). That is, the stage drive system 23 applies a force from an arbitrary motor to the stage 22, for example, to move the stage 22. When the stage 22 moves, the sample W held by the stage 22 also moves. Therefore, it can be said that the stage drive system 23 substantially applies a force from an arbitrary motor to the sample W via the stage 22 to move the sample W. Further, the stage device 2 includes a position measuring device 24 for measuring the position of the stage 22. The position measuring device 24 includes, for example, at least one of an encoder and a laser interferometer. When the stage 22 holds the sample W, the control device 4 can specify the position of the sample W from the position of the stage 22. The stage 22 may have a reference plate provided with a reference mark for associating the position of the electron beam EB by the beam irradiation device 1 with the position of the stage 22 (position in the XYZ direction).

When the stage 22 moves, the relative position between the stage 22 and the beam irradiation device 1 changes. Further, when the stage 22 moves, the relative positions of the sample W supported by the stage 22 and the beam irradiation device 1 change. Therefore, the stage drive system 23 may function as a position change device capable of changing the relative position between the stage 22 and / or the sample W and the beam irradiation device 1.

When the stage 22 moves along the XY plane, the relative position of the sample W and the beam irradiator 1 in the direction along the XY plane changes. Therefore, when the stage 22 moves along the XY plane, the sample W in the direction along the XY plane and the irradiation region of the electron beam EB on the surface of the sample W (specifically, the surface facing the + Z side) WSu. The relative position of is changed. That is, when the stage 22 moves along the XY plane, the irradiation region of the electron beam EB moves with respect to the surface WSu of the sample W in the direction along the XY plane (that is, the direction along the surface WSu of the sample W). To do. Further, when the stage 22 moves along the XY plane, the relative position of the sample W and the vacuum region VSP in the direction along the XY plane changes. Therefore, when the stage 22 moves along the XY plane, the vacuum region VSP moves with respect to the surface WSu of the sample W in the direction along the XY plane. In this case, the control device 4 controls the stage drive system 23 so that the electron beam EB is irradiated to the desired position of the surface WSu of the sample W and the vacuum region VSP is formed, and the stage 22 is moved along the XY plane. You may move it. As a result, even if the stage 22 moves, the passage of the electron beam EB (that is, the path or space in which the electron beam EB propagates) between the electron beam irradiation device 1 and the sample W is at least a part of the vacuum region VSP. include. That is, the scanning electron microscope SEMa can irradiate the sample W with the electron beam EB via the vacuum region VSP even if the stage 22 moves.

When the vacuum region VSP moves relative to the surface WSu of the sample W as the stage 22 moves along the XY plane, the position of the portion of the sample W on which the negative pressure caused by the vacuum region VSP acts changes. .. As a result, there is a possibility that a biased force acts on the sample W, especially when the negative pressure caused by the vacuum region VSP acts near the outer edge of the sample W. As a result, a biased force may also act on the stage 22 that holds the sample W. Therefore, the negative pressure caused by the vacuum region VSP acts near the outer edge of the sample W (that is, the stage) as compared with the case where the negative pressure caused by the vacuum region VSP acts near the center of the sample W. If a biased force acts on 22), the stage 22 may be easily deformed. Therefore, in the stage 22, even if the position of the portion of the sample W on which the negative pressure due to the vacuum region VSP acts changes, the stage 22 does not deform or the amount of deformation of the stage 22 becomes equal to or less than the allowable lower limit amount. It may have a relatively high rigidity to some extent.

When the stage 22 moves along the Z axis, the relative position of the sample W and the beam irradiator 1 in the direction along the Z axis changes. Therefore, when the stage 22 moves along the Z axis, the relative position between the sample W and the focus position FP of the electron beam EB in the direction along the Z axis changes. The control device 4 controls the stage drive system 23 so that the focus position FP of the electron beam EB is set on the surface WSu of the sample W (or in the vicinity of the surface WSu) so that the stage 22 is moved along the Z axis. You may move it. Here, the focus position FP of the electron beam EB has the least blurring of the focus position or the electron beam EB corresponding to the imaging position of the beam optical system 11 (see FIG. 2) described later included in the electron beam irradiation device 1. It may be a position in the Z-axis direction.

Further, when the stage 22 moves along the Z axis, the distance D between the sample W and the beam irradiation device 1 changes. Therefore, the stage drive system 23 may move the stage 22 under the control of the control device 4 so that the interval D becomes the desired interval D_taget in cooperation with the interval adjusting system 14 described later. At this time, the control device 4 is based on the measurement result of the position measurement device 24 (furthermore, the measurement result of the position measurement device 15 that measures the position of the beam irradiation device 1 (particularly, the position of the vacuum forming member 121) described later). Therefore, the actual interval D is specified, and at least one of the stage drive system 23 and the interval adjusting system 14 is controlled so that the specified interval D becomes the desired interval D_taget. Therefore, the

position measuring devices

15 and 24 can also function as a detecting device for detecting the interval D. When the thickness (dimension) of the sample W in the Z-axis direction is known, the control device 4 replaces or adds to the actual interval D with the beam irradiation device 1 and the reference surface (for example, the surface of the reference plate). Using the information about the distance in the Z-axis direction of the sample W and the information about the thickness (dimensions) of the sample W in the Z-axis direction, the distance D between the beam irradiation device 1 and the sample W is set to the desired distance D_target. At least one of the stage drive system 23 and the interval adjustment system 14 may be controlled.

When the stage 22 moves along at least one of the θX direction and the θY direction (furthermore, the stage 22 moves along the θZ direction as necessary), the relative posture of the sample W with respect to the beam irradiation device 1 (moreover, the relative posture of the sample W with respect to the beam irradiation device 1 Specifically, it is the amount of inclination, and the tilt angle) changes substantially. The control device 4 controls the stage drive system 23 to move the stage 22 along at least one of the θX direction, the θY direction, and the θZ direction so that the sample W is in an appropriate posture with respect to the beam irradiation device 1. You may. For example, the control device 4 controls the stage drive system 23 so that the surface WSu of the sample W is parallel to the injection surface 12LS (see FIG. 2) of the beam irradiation device 1 described later, and moves the stage 22 in the θX direction. , The θY direction and the θZ direction may be moved along at least one of the directions. In the present embodiment, the state in which "the surface B is parallel to the surface A" is designated as "one of the surface A and the surface B is designated as a datum plane (a plane that serves as a reference for obtaining a geometrical tolerance)". In this case, it means that either one of the surface A and the surface B fits between two virtual surfaces parallel to the datum plane and separated by a desired distance. For example, the desired distance may be smaller than the desired interval D_target described above. For example, the desired distance may be a value of 1/10 or less of the desired interval D_target described above.

The support frame 3 supports the beam irradiation device 1. Specifically, the support frame 3 includes a support leg 31 and a support member 32. The support legs 31 are arranged on the support surface SF. An anti-vibration device (not shown) may be installed between the support leg 31 and the support surface SF to prevent or reduce the transmission of the vibration of the support surface SF to the support leg 31. The support leg 31 is, for example, a member extending upward from the support surface SF. The support legs 31 support the support member 32. The support member 32 is an annular plate member having an opening 321 formed in the center in a plan view. The lower surface of the flange member 13 extending outward from the outer surface of the beam irradiation device 1 is connected to the upper surface of the support member 32 via an interval adjusting system 14. At this time, the beam irradiation device 1 is arranged so as to penetrate the opening 321. As a result, the support frame 3 can support the beam irradiation device 1 so as to be lifted by the upper surface of the support member 32. In this case, the support frame 3 may function as a stopper for preventing the beam irradiation device 1 from moving toward the sample W so as to prevent the beam irradiation device 1 from colliding with the sample W. However, the support frame 3 may support the beam irradiation device 1 by a support method different from the support method shown in FIG. 1 as long as the beam irradiation device 1 can be supported. For example, instead of supporting the support frame 3 by the support legs 31, the support frame 3 may be supported by a suspension support mechanism. In this case, the anti-vibration pad is fixed to the top plate (ceiling wall) of the chamber accommodating the support frame 3, one end is connected to the lower end of the anti-vibration pad, and the other end of the wire made of steel is connected to the support frame 3. You may. The anti-vibration pad may include, for example, an air damper and / or a coil spring. A vibration isolator (not shown) may be installed between the support legs 31 and the support member 32 to prevent or reduce the transmission of the vibration of the support surface SF to the support member 32.

As described above, when the vacuum region VSP is formed between the beam irradiation device 1 and the sample W, the negative pressure caused by the vacuum region VSP acts on the beam irradiation device 1 toward the vacuum region VSP. A force that pulls the beam irradiation device 1 (that is, toward the sample W) acts. This force also acts on the support frame 3 that supports the beam irradiation device 1. Therefore, in the support frame 3, the support frame 3 is not deformed or the deformation amount of the support frame 3 is less than the allowable lower limit amount even when the force caused by the formation of the vacuum region VSP acts on the support frame 3. It may have a relatively high rigidity to some extent.

The interval adjusting system 14 moves the beam irradiation device 1 along at least the Z axis so that the distance D between the beam irradiation device 1 and the sample W (or the Z-axis direction from the beam irradiation device 1 to the sample W) Distance) is adjusted. For example, the interval adjusting system 14 may move the beam irradiation device 1 along the Z-axis direction so that the interval D becomes a desired interval D_taget. For example, the interval adjusting system 14 applies a desired force to the flange member 13 (that is, the beam irradiating device 1) to move the beam irradiating device 1. When the beam irradiation device 1 includes the beam optical system 11 and the differential exhaust system 12 as described later (see FIG. 2), the interval adjusting system 14 applies a desired force to the beam optical system 11 and the differential exhaust system. It can be said that the beam optical system 11 and the differential exhaust system 12 are moved by indirectly applying to the system 12. In this case, as the interval adjusting system 14, for example, a drive system that moves the beam irradiation device 1 by using the driving force of the motor, and a drive system that moves the beam irradiation device 1 by using the force generated by the piezoelectric effect of the piezo element. A drive system that moves the beam irradiation device 1 using a Coulomb force (for example, an electrostatic force generated between at least two electrodes) and a Lorentz force (for example, an electromagnetic force generated between a coil and a magnetic pole) are used. At least one of the drive systems for moving the beam irradiation device 1 may be used. However, if the distance D between the beam irradiation device 1 and the surface WSu of the sample W may remain fixed (or the space adjustment system 14 does not have to adjust the space D), the space adjustment system Instead of 14, an interval adjusting member such as a shim may be arranged between the support member 32 and the flange member 13. In this case, if the size and / or number of shims is changed, the interval D will be adjusted. Further, the interval adjusting system 14 may move the beam irradiation device 1 along at least one of the X-axis direction, the Y-axis direction, the θX direction, the θY direction, and the θZ direction. In this case, the interval adjusting system 14 may be referred to as a position changing device.

In order to measure the position of the beam irradiation device 1 movable by the interval adjusting system 14 in the Z direction (particularly, the position of the vacuum forming member 121 in the Z direction), the scanning electron microscope SEMa includes a position measuring device 15. There is. The position measuring device 15 includes, for example, at least one of an encoder and a laser interferometer. The position measuring device 15 may measure the position of the beam irradiation device 1 in the XY direction, the posture in the θX direction, and the posture in the θY direction. Further, a measuring device for measuring the position of the beam irradiation device 1 in the XY direction, the posture in the θX direction, and the posture in the θY direction may be provided separately from the position measuring device 15.

The control device 4 controls the operation of the scanning electron microscope SEMa. The control device 4 may include, for example, an arithmetic unit and a memory. The arithmetic unit may include at least one of a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), and an MCU (Micro Control Unit). The control device 4 functions as a device that controls the operation of the scanning electron microscope SEMa by executing a computer program by the arithmetic unit. This computer program is a computer program for causing the control device 4 (for example, an arithmetic unit) to perform (that is, execute) an operation described later to be performed by the control device 4. That is, this computer program is a computer program for making the control device 4 function so that the scanning electron microscope SEMa performs the operation described later. The computer program executed by the arithmetic unit may be recorded in a memory (that is, a recording medium) included in the control device 4, or may be an arbitrary storage medium built in the control device 4 or externally attached to the control device 4. It may be recorded in (for example, a hard disk or a semiconductor memory). Alternatively, the arithmetic unit may download the computer program to be executed from an external device of the control device 4 via the network interface.

For example, the control device 4 controls the beam irradiation device 1 so as to irradiate the sample W with the electron beam EB. For example, the control device 4 controls at least one of the beam irradiation device 1 and the stage drive system 23 so that the electron beam EB is irradiated to a desired position in the XY plane of the surface WSu of the sample W. For example, the control device 4 controls at least one of the stage drive system 23 and the interval adjustment system 14 so that the interval D between the beam irradiation device 1 and the sample W becomes the desired interval D_target. For example, the control device 4 controls at least one of the interval adjusting system 14 and the stage drive system 23 so that the injection surface 12LS of the beam irradiation device 1 is parallel to the surface WSu of the sample W.

The control device 4 may not be provided inside the scanning electron microscope SEMa, and may be provided as a server or the like outside the scanning electron microscope SEMa, for example. In this case, the control device 4 and the scanning electron microscope SEMA may be connected by a wired and / or wireless network (or a data bus and / or a communication line). As the wired network, for example, a network using a serial bus type interface represented by at least one of IEEE1394, RS-232x, RS-422, RS-423, RS-485 and USB may be used. As the wired network, a network using a parallel bus interface may be used. As a wired network, a network using an Ethernet (registered trademark) compliant interface represented by at least one of 10BASE-T, 100BASE-TX and 1000BASE-T may be used. As the wireless network, a network using radio waves may be used. An example of a network using radio waves is a network conforming to IEEE802.1x (for example, at least one of wireless LAN and Bluetooth®). As the wireless network, a network using infrared rays may be used. As the wireless network, a network using optical communication may be used. In this case, the control device 4 and the scanning electron microscope SEMa may be configured so that various types of information can be transmitted and received via the network. Further, the control device 4 may be able to transmit information such as commands and control parameters to the scanning electron microscope SEMa via the network. The scanning electron microscope SEMa may include a receiving device that receives information such as commands and control parameters from the control device 4 via the network.

The recording medium for recording the computer program executed by the arithmetic unit includes CD-ROM, CD-R, CD-RW, flexible disk, MO, DVD-ROM, DVD-RAM, DVD-R, DVD + R, and DVD-. At least one of optical disks such as RW, DVD + RW and Blu-ray (registered trademark), magnetic media such as magnetic tape, magneto-optical disks, semiconductor memories such as USB memory, and any other medium capable of storing a program is used. You may. The recording medium may include a device capable of recording a computer program (for example, a general-purpose device or a dedicated device in which the computer program is implemented in at least one form such as software and firmware). Further, each process or function included in the computer program may be realized by a logical processing block realized in the control device 4 by the control device 4 (that is, a computer) executing the computer program. It may be realized by hardware such as a predetermined gate array (FPGA, ASIC) included in the control device 4, or a logical processing block and a partial hardware module that realizes a part of the hardware are mixed. It may be realized in the form of.

(1-2) Structure of Beam Irradiation Device 1 Subsequently, the structure of the beam irradiation device 1 of the first embodiment will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the structure of the beam irradiation device 1 of the first embodiment.

As shown in FIG. 2, the beam irradiation device 1 includes a beam optical system 11 and a differential exhaust system 12.

The beam optical system 11 includes a housing 111. The housing 111 is a cylindrical member in which a beam passing space SPb1 extending along the optical axis AX of the beam optical system 11 (that is, extending along the Z axis) is secured inside. The beam passing space SPb1 is used as a space through which the electron beam EB passes. To prevent the electron beam EB passing through the beam passing space SPb1 from passing through the housing 111 (that is, leaking to the outside of the housing 111) and / or the magnetic field outside the beam irradiation device 1 (so-called disturbance). The housing 111 may be made of a high magnetic permeability material in order to prevent the magnetic field) from affecting the electron beam EB passing through the beam passing space SPb1. Examples of high magnetic permeability materials include at least one of permalloy and silicon steel. The relative magnetic permeability of these high magnetic permeability materials is 1000 or more.

The beam passing space SPb1 becomes a vacuum space during the period when the electron beam EB is irradiated. Specifically, the beam passage space SPb1 is connected to the beam passage space SPb1 via an exhaust passage (that is, a pipeline, the same applies hereinafter) 112 formed in the housing 111 so as to be connected to (that is, connected to) the beam passage space SPb1. The vacuum pump 51 is connected. The vacuum pump 51 exhausts the beam passing space SPb1 (that is, discharges gas) so that the beam passing space SPb1 becomes a vacuum space, and depressurizes the pressure below the atmospheric pressure. Therefore, the vacuum space in the first embodiment may mean a space whose pressure is lower than the atmospheric pressure. In particular, the vacuum space is a space in which gas molecules exist only to the extent that the electron beam EB does not interfere with the appropriate irradiation of the sample W (in other words, the degree of vacuum does not interfere with the appropriate irradiation of the electron beam EB with the sample W). Space) may be meant. The beam passing space SPb1 is a space outside the housing 111 (more specifically, a differential exhaust system 12 described later) via a beam ejection port (that is, an opening) 119 formed on the lower surface of the housing 111. It is connected to the beam passage space SPb2). The beam passing space SPb1 may be a vacuum space during the period when the electron beam EB is not irradiated.

The beam optical system 11 further includes an electron gun 113, an electromagnetic lens 114, an objective lens 115, a deflector 116, and an electron detector 117. The electron gun 113 emits an electron beam EB toward the −Z side. Instead of the electron gun 113, a photoelectric conversion surface that emits electrons when irradiated with light may be used. The electron gun 113 emits an electron beam EB toward the −Z side. Instead of the electron gun 113, a photoelectric conversion surface that emits electrons when irradiated with light may be used. The electromagnetic lens 114 controls the electron beam EB emitted by the electron gun 113. For example, the electromagnetic lens 114 has an image rotation amount (that is, a position in the θZ direction) formed by the electron beam EB on a predetermined optical surface (for example, a virtual surface intersecting the optical path of the electron beam EB), and a magnification of the image. , And any one of the focal positions corresponding to the imaging position may be controlled. The objective lens 115 forms an electron beam EB on the surface WSu of the sample W at a predetermined reduction magnification. The deflector 116 deflects the electron beam EB so that the irradiation position of the electron beam EB on the surface WSu of the sample W (particularly, the direction along the surface WSu (for example, the direction along at least one of the X-axis and the Y-axis)). ) Is controlled. The electron detector 117 is, for example, a semiconductor type electron detection device (that is, a semiconductor detection device) using a pn junction or pin junction semiconductor. As the electron detector 117, for example, at least one of an ET (Everhard-Tornley) detector in which a scintillator (fluorescent substance) and a photomultiplier tube are combined and a micro-channel plate (MCP) may be used. .. The control device 4 acquires (in other words, obtains, calculates, or generates) information about the sample W based on the detection result of the electron detector 117.

Specifically, in order to acquire information about the sample W, the control device 4 irradiates the sample W with the electron beam EB so as to scan the surface WSu of the sample W with the electron beam EB, for example. Specifically, the scanning electron microscope SEMa controls the stage drive system 23 to move the stage 22 along the XY plane so that the vacuum region VSP is formed on the first surface portion of the surface WSu of the sample W. Let me. After the stage 22 moves so that the vacuum region VSP is formed on the first surface portion of the surface WSu of the sample W, the beam irradiation device 1 irradiates the first surface portion of the surface WSu of the sample W with the electron beam EB. .. At this time, the beam irradiation device 1 scans the first surface portion with the electron beam EB by deflecting the electron beam EB using the deflector 116 (see FIG. 2) described later included in the beam irradiation device 1. During the period in which the beam irradiation device 1 irradiates the first surface portion of the surface WSu of the sample W with the electron beam EB, the stage drive system 23 does not have to move the stage 22 along the XY plane. After the scanning of the first surface portion with the electron beam EB is completed, the scanning electron microscope SEMa controls the stage drive system 23 so that the vacuum region VSP is formed on the second surface portion of the surface WSu of the sample W. Then, the stage 22 is moved along the XY plane. After the stage 22 moves so that the vacuum region VSP is formed on the second surface portion of the surface WSu of the sample W, the beam irradiation device 1 irradiates the second surface portion of the surface WSu of the sample W with the electron beam EB. .. At this time, the beam irradiation device 1 scans the second surface portion with the electron beam EB by deflecting the electron beam EB using the deflector 116. The stage drive system 23 does not have to move the stage 22 along the XY plane also during the period when the beam irradiation device 1 irradiates the second surface portion of the surface WSu of the sample W with the electron beam EB. After that, the same process is repeated until the irradiation (that is, scanning) of the electron beam EB to the target region of the surface WSu of the sample W to be irradiated with the electron beam EB is completed.

When the sample W is irradiated with the electron beam EB, the electrons generated by the irradiation of the sample W with the electron beam EB are emitted from the sample W. The electrons generated by the irradiation of the sample W with the electron beam EB include at least one of the reflected electrons from the sample W and the scattered electrons from the sample W. The scattered electrons may include secondary electrons. The electrons generated by the irradiation of the sample W with the electron beam EB are detected by the electron detector 117. Therefore, the detection result of the electron detector 117 may include information on the detection amount of electrons generated when the sample W is irradiated with the electron beam EB. The electronic detector 117 may be provided in the differential exhaust system 12 described later. Alternatively, the detection result of the electron detector 117 may be, in addition to or in place of the information regarding the amount of detected electrons, information regarding the electrons generated when the sample W is irradiated with the electron beam EB (for example, the velocity and incident angle of the electrons). Information on at least one of the above) may be included.

The control device 4 generates (that is, acquires) information about the sample W based on the detection result of the electron detector 117. For example, the control device 4 may generate information (hereinafter, referred to as “image information”) regarding the image of the sample W based on the detection result of the electron detector 117. In particular, the image information may include information about the image of the surface WSu of the sample W. Specifically, the electron detector 117 detects the electrons generated when the electron beam EB is irradiated while the beam irradiation device 1 is scanning the surface WSu of the sample W with the electron beam EB. As a result, in accordance with the scanning of the surface WSu by the electron beam EB, the electron detector 117 is, for example, the electrons generated when the electron beam EB is irradiated to the first position of the surface WSu of the sample W, the sample W. The electrons generated when the electron beam EB is irradiated to the second position of the surface WSu, ..., And the electron beam EB is located at the Kth position (where K is an integer of 2 or more) of the surface WSu of the sample W. Detects the electrons generated when irradiated. In this case, the control device 4 can generate information regarding the distribution of the detected amount of electrons based on the detection result of the electron detector 117. That is, the control device 4 has an image having characteristics according to the amount of detected electrons based on the detection result of the electron detector 117 (that is, information on the detection result of electrons) and the information on the irradiation position of the electron beam EB. Image information regarding (a so-called SEM image, and in the first embodiment, an image of the surface WSu of the sample W) can be generated.

The differential exhaust system 12 is a member extending downward from the beam optical system 11. The differential exhaust system 12 is arranged below the beam optical system 11 (that is, on the −Z side). The differential exhaust system 12 is connected (that is, connected) to the beam optical system 11 below the beam optical system 11. For example, the differential exhaust system 12 may be connected to the beam optical system 11 so that the upper surface of the differential exhaust system 12 is connected to the lower surface of the beam optical system 11. For example, the differential exhaust system 12 may be connected to the beam optical system 11 via an airtight member. Examples of the airtight member include at least one of an O-ring and a bellows. The differential exhaust system 12 may be integrated with the beam optical system 11 or may be separable from the beam optical system 11.

A beam passage space SPb2 is formed inside the differential exhaust system 12. The beam passage space SPb2 is connected to the beam passage space SPb1 of the beam optical system 11 via an opening 120 formed on the upper surface of the differential exhaust system 12 (the surface on the + Z side in the example shown in FIG. 2). .. The beam passing space SPb2 is exhausted (that is, depressurized) by the vacuum pump 51 together with the beam passing space SPb1. Therefore, the beam passing space SPb2 becomes a vacuum space during the period in which the electron beam EB is irradiated. The beam passing space SPb2 is used as a space through which the electron beam EB from the beam passing space SPb1 passes. To prevent the electron beam EB passing through the beam passage space SPb2 from passing through the differential exhaust system 12 (that is, leaking to the outside of the differential exhaust system 12) and / or a magnetic field outside the beam irradiation device 1. At least a part of the differential exhaust system 12 may be made of a high magnetic permeability material in order to prevent (so-called disturbance magnetic field) from affecting the electron beam EB passing through the beam passing space SPb2. .. The beam passing space SPb2 may be a vacuum space during the period when the electron beam EB is not irradiated.

The differential exhaust system 12 further includes an injection surface 12LS capable of facing a part of the surface VSu of the sample W. In the beam irradiation device 1, the distance D between the injection surface 12LS and the surface VSu of the sample W (that is, the distance D between the beam irradiation device 1 and the surface VSu in the Z-axis direction) is a desired distance D_stage (for example, 10 μm). It is aligned with respect to the surface VSu by at least one of the stage drive system 23 and the interval adjustment system 14 so as to be less than or equal to 1 μm or more). The distance D may be referred to as the distance between the injection surface 12LS and the surface WSu in the Z-axis direction. Further, the interval adjusting system 14 may be referred to as an interval control device. A beam ejection port (that is, an opening) 1250 is formed on the ejection surface 12LS. The differential exhaust system 12 does not have to have an injection surface 12LS capable of facing the surface WSu of the sample W.

The beam passing space SPb2 is connected to the beam passing space SPb3 outside the differential exhaust system 12 via the beam injection port 1250. That is, the beam passing space SPb1 is connected to the beam passing space SPb3 via the beam passing space SPb2. Therefore, the beam ejection port 1250 is the end portion of the beam passing space SPb2 (or the space including the beam passing spaces SPb1 and BPb2) on the sample W side. However, the beam passage space SPb2 may not be secured. That is, the beam passing space SPb1 may be directly connected to the beam passing space SPb3 without passing through the beam passing space SPb2. The beam passage space SPb3 is a space (for example, a local space) on the surface WSu of the sample W. The beam passage space SPb3 is a space in contact with (that is, faces) the surface WSu of the sample W. The beam passage space SPb3 is a space through which the electron beam EB passes between the beam irradiation device 1 and the sample W (specifically, between the injection surface 12LS and the surface WSu). The beam passing space SPb3 is exhausted (that is, depressurized) by the vacuum pump 51 together with the beam passing spaces SPb1 and SPb2. That is, the vacuum pump 51 exhausts the beam passing space SPb3 in a state where the differential exhaust system 12 (particularly, the injection surface 12LS) faces a part of the surface WSu of the sample W. The vacuum pump 51 exhausts the beam passing space SPb3 in a state where the beam passing space SPb2 (particularly, the end portion thereof, substantially the beam ejection port 1250) faces a part of the surface WSu of the sample W. In this case, each of the beam passing spaces SP1 and SPb2 can also function as an exhaust passage (that is, a pipeline) connecting the beam passing space SPb3 and the vacuum pump 51 in order to exhaust the beam passing space SPb3. As a result, the beam passing space SPb3 becomes a vacuum space during the period in which the electron beam EB is irradiated. Therefore, the electron beam EB emitted from the electron gun 113 irradiates the sample W through at least a part of the beam passing spaces SPb1 to SPb3, which are vacuum spaces. The beam passing space SPb3 may be a vacuum space during the period when the electron beam EB is not irradiated.

The beam passing space SPb3 is located farther from the vacuum pump 51 than the beam passing spaces SPb1 and SPb2. The beam passing space SPb2 is located at a position farther from the vacuum pump 51 than the beam passing space SPb1. Therefore, the degree of vacuum of the beam passing space SPb3 may be lower than the degree of vacuum of the beam passing spaces SPb1 and SPb2, and the degree of vacuum of the beam passing space SPb2 is higher than the degree of vacuum of the beam passing space SPb1. It can be low. The state of "the degree of vacuum in space B is lower than the degree of vacuum in space A" in the present embodiment means "the pressure in space B is higher than the pressure in space A". In this case, the vacuum pump 51 can set the vacuum degree of the beam passing space SPb3, which may have the lowest vacuum degree, to a vacuum degree that does not interfere with the appropriate irradiation of the electron beam EB on the sample W. Has exhaust capacity. As an example, the vacuum pump 51 maintains the pressure (ie, air pressure) of the beam passage space SPb3 below 1 × 10 ^-3 pascals (eg, approximately on the order of 1 × 10 ^-3 pascals to 1 × 10 ^-4 pascals). It may have an exhaust capacity that can be maintained). Such a vacuum pump 51 is used, for example, as a turbo molecular pump used as a main pump (or another type of high vacuum pump including at least one of a diffusion pump, a cryo pump and a sputter ion pump) and an auxiliary pump. A vacuum pump combined with a dry pump (or another type of low vacuum pump) may be used. The exhaust speed of the vacuum pump 51 may be an exhaust speed [m ³ / s] that can maintain the pressure (that is, atmospheric pressure) of the beam passing space SPb3 at 1 × 10 ^-3 pascal or less. ..

However, the beam passing space SPb3 is not a closed space surrounded by some member (specifically, the housing 111 and the differential exhaust system 12) like the beam passing spaces SPb1 and SPb2. That is, the beam passing space SPb3 is an open space that is not surrounded by any member. Therefore, even if the beam passing space SPb3 is decompressed by the vacuum pump 51, gas flows into the beam passing space SPb3 from the periphery of the beam passing space SPb3. As a result, the degree of vacuum of the beam passing space SPb3 may decrease. Therefore, the differential exhaust system 12 maintains the degree of vacuum in the beam passing space SPb3 by performing differential exhaust between the beam irradiation device 1 and the surface WSu of the sample W. That is, the differential exhaust system 12 performs differential exhaust between the beam irradiation device 1 and the surface WSu of the sample W, so that the beam irradiation device 1 and the sample W are relative to each other as compared with the surroundings. A vacuum region VSP (for example, a local vacuum region VSP) in which a high degree of vacuum is maintained is formed.

In order to perform differential exhaust, two annular exhaust ports 1251 and 1252 (or at least one exhaust port of any shape) surrounding the beam injection port 1250 are formed on the injection surface 12LS of the differential exhaust system 12. Has been done. The

exhaust ports

1251 and 1252 can also be said to be exhaust grooves (in other words, recesses, the same applies hereinafter). A vacuum pump 52 is connected to the exhaust port 1251 via an exhaust passage (that is, a pipeline, the same applies hereinafter) EP1 formed in the differential exhaust system 12. That is, the first end (that is, one end) of the exhaust passage EP1 is connected to the vacuum pump 52 and is the second end (that is, the other end) of the exhaust passage EP1, which is substantially the exhaust port. The portion forming 1251) is in contact with the space between the injection surface 12LS and the surface WSu of the sample W. A vacuum pump 52 is connected to the exhaust port 1252 via an exhaust passage (that is, a pipeline, the same applies hereinafter) EP2 formed in the differential exhaust system 12. That is, the first end (that is, one end) of the exhaust passage EP2 is connected to the vacuum pump 52 and is the second end (that is, the other end) of the exhaust passage EP2, which is substantially the exhaust port. The portion forming 1252) is in contact with the space between the injection surface 12LS and the surface WSu of the sample W. Therefore, the differential exhaust system 12 is provided via a first-stage exhaust path composed of the exhaust passage EP1 and the exhaust port 1251 and a second-stage exhaust path composed of the exhaust passage EP2 and the exhaust port 1252. , Differential exhaust can be performed between the beam irradiation device 1 and the surface WSu of the sample W. That is, in the example shown in FIG. 2, the differential exhaust system 12 is a differential exhaust system in which the number of exhaust stages is set to two. However, the number of exhaust stages of the differential exhaust system 12 is not limited to two, and when the number of exhaust stages is not two, the number of exhaust ports formed on the injection surface 12LS and the exhaust ports are connected to the exhaust ports. The number of exhaust passages is appropriately set according to the number of exhaust stages.

In this case, the vacuum pump 52 passes the beam passage space SPb3 through the exhaust passages EP1 and EP2 in a state where the differential exhaust system 12 (particularly, the injection surface 12LS) faces a part of the surface WSu of the sample W. Exhaust. The vacuum pump 52 has a beam passage space SPb3 in a state where the exhaust passages EP1 and EP2 (particularly, the ends thereof, substantially the exhaust ports 1251 and 1252) face a part of the surface WSu of the sample W. Exhaust. As a result, the differential exhaust system 12 can form a vacuum region VSP including the beam passing space SPb3 between the beam irradiation device 1 and the surface WSu of the sample W. In the differential exhaust in the present embodiment, one space (for example, the beam passing space SPb3) and another space different from one space are provided between the surface WSu of the sample W and the beam irradiating device 1. It corresponds to exhausting the beam passage space SPb3 while utilizing the property that the pressure difference between the samples W is maintained by the exhaust resistance of the gap between the surface WSu of the sample W and the beam irradiation device 1. Since the beam passage space SPb3 covers at least a part of the surface WSu of the sample W, the vacuum region VSP also locally covers at least a part of the surface WSu of the sample W. That is, the vacuum region VSP is in contact with (ie, faces) at least a portion of the surface WSu of the sample W.

The vacuum pump 52 mainly exhausts at least a part of the space around the beam passing space SPb3 (particularly, the space located around the space where the vacuum region VSP is formed and having a higher pressure than the vacuum region VSP). It is used to relatively increase the degree of vacuum of the beam passage space SPb3. Therefore, the vacuum pump 52 may have an exhaust capacity capable of maintaining a vacuum degree lower than the vacuum degree maintained by the vacuum pump 51. That is, the exhaust capacity of the vacuum pump 52 may be lower than the exhaust capacity of the vacuum pump 51. For example, the vacuum pump 52 may be a vacuum pump that includes a dry pump (or another type of low vacuum pump) but not a turbo molecular pump (or another type of high vacuum pump). Good. In this case, even if the degree of vacuum in the spaces in the exhaust ports 1251 to 1252 and the exhaust passages EP1 to EP2 decompressed by the vacuum pump 52 is lower than the degree of vacuum in the beam passage spaces SPb1 to SPb3 decompressed by the vacuum pump 51. Good. The exhaust speed of the vacuum pump 52 may be an exhaust speed [m ³ / s] that can maintain a vacuum degree lower than the vacuum degree maintained by the vacuum pump 51.

However, considering the principle of differential exhaust that forms a vacuum region VSP using exhaust resistance, the region that exhausts through a certain exhaust path among the multiple stages of exhaust paths is close to the beam passage space SPb3 (in other words,). , The closer to the beam injection port 1250), the greater the contribution of the degree of vacuum of the exhaust path to increase the degree of vacuum of the beam passage space SPb3. Therefore, in the differential exhaust system 12, the degree of vacuum of the first-stage exhaust path (that is, the exhaust path from the exhaust port 1251 to the vacuum pump 52) composed of the exhaust passage EP1 and the exhaust port 1251 is exhausted. Even if differential exhaust is performed so that the degree of vacuum is higher than the degree of vacuum of the second stage exhaust path (that is, the exhaust path from the exhaust port 1252 to the vacuum pump 52) composed of the passage EP2 and the exhaust port 1252. Good.

For example, the length of the exhaust path affects the degree of vacuum of the exhaust path. Therefore, the length of the first-stage exhaust path may be different from the length of the second-stage exhaust path. Typically, under the condition that the exhaust path is exhausted at the same exhaust rate, the shorter the exhaust path, the more likely it is that the degree of vacuum in the exhaust path will increase. This is because the shorter the exhaust path, the smaller the space in which the gas molecules exist (that is, the space to be exhausted). Therefore, the exhaust path of the first stage may be shorter than the exhaust path of the second stage.

For example, the volume of the exhaust path affects the degree of vacuum of the exhaust path. Therefore, the volume of the first-stage exhaust path may be different from the volume of the second-stage exhaust path. Typically, under the condition that the exhaust path is exhausted at the same exhaust rate, the smaller the volume of the exhaust path, the higher the possibility that the degree of vacuum of the exhaust path increases. This is because the smaller the volume of the exhaust path, the smaller the space in which the gas molecules exist (that is, the space to be exhausted). Therefore, the volume of the first-stage exhaust path may be smaller than the volume of the second-stage exhaust path.

For example, the area of the inner surface of the exhaust path affects the degree of vacuum of the exhaust path. Therefore, the area of the inner surface of the first-stage exhaust path may be different from the area of the inner surface of the second-stage exhaust path. Typically, under the condition that the exhaust path is exhausted at the same exhaust rate, the smaller the area of the inner surface of the exhaust path, the higher the possibility that the degree of vacuum of the exhaust path increases. This is because the shorter the area of the inner surface of the exhaust path, the smaller the inner surface where the gas molecules are present in the exhaust path (that is, the region where the gas molecules should be recovered by the exhaust gas). Therefore, the area of the inner surface of the first-stage exhaust path may be smaller than the area of the inner surface of the second-stage exhaust path.

While the vacuum region VSP including the beam passage space SPb3 is formed in this way, at least the portion of the surface WSu of the sample W that does not face the beam passage space SPb3 (particularly, the portion away from the beam passage space SPb3) is formed. A part may be covered with a non-vacuum region having a lower degree of vacuum than the vacuum region VSP. Specifically, the differential exhaust system 12 forms a vacuum region VSP in the space SP1 (see the enlarged view at the bottom of FIG. 2) including the beam passing space SPb3. The space SP1 includes, for example, a space in contact with at least one of the beam injection port 1250 and the

exhaust ports

1251 and 1252. The space SP1 includes a space facing a portion of the surface WSu of the sample W located directly below at least one of the beam injection port 1250 and the

exhaust ports

1251 and 1252. On the other hand, the vacuum region VSP is not formed in the space SP2 around the space SP1 (that is, the space SP2 connected to the space SP2 around the space SP1 and see the enlarged view at the bottom of FIG. 2). That is, the space SP2 is a space having a higher pressure than the space SP1. The space SP2 includes, for example, a space away from the beam outlet 1250 and the

exhaust ports

1251 and 1252. The space SP2 includes a space that cannot be connected to the beam injection port 1250, the exhaust ports 1251 and 1252 (furthermore, the beam passage space SPb2, the exhaust passage EP1 and the exhaust passage EP2) without passing through the space SP1. The space SP2 includes a space that can be connected to the beam injection port 1250, the exhaust ports 1251 and 1252 (furthermore, the beam passage space SPb2, the exhaust passage EP1 and the exhaust passage EP2) via the space SP1. Since the pressure in the space SP2 is higher than the pressure in the space SP1, there is a possibility that gas may flow from the space SP2 into the space SP1, but the gas flowing from the space SP2 into the space SP1 is the outermost exhaust. It is discharged from the space SP1 through the port 1252 (further, the exhaust port 1251 and the beam injection port 1250). That is, the gas flowing from the space SP2 into the space SP1 is discharged from the space SP1 via the exhaust passage EP2 (furthermore, the exhaust passage EP1 and the beam passage space SPb2). Therefore, the degree of vacuum in the vacuum region formed in the space SP1 is maintained. As described above, the state in which the vacuum region VSP is locally formed is the state in which the vacuum region VSP is locally formed on the surface WSu of the sample W (that is, the vacuum region in the direction along the surface WSu of the sample W). It may mean a state in which VSP is locally formed).

As described above, the vacuum region VSP is a region in which gas molecules are present only to such an extent that the electron beam EB irradiates the sample W appropriately. Specifically, the vacuum region VSP is, for example, a region where the pressure is 1 × 10 ^-3 Pascal or less (for example, generally on the order of 1 × 10 ^-3 Pascal to 1 × 10 ^-4 Pascal). That is, the pressure of the space SP1 in which the vacuum region VSP is formed is 1 × 10 ^-3 Pascal or less (for example, approximately on the order of 1 × 10 ^-3 Pascal to 1 × 10 ^-4 Pascal). On the other hand, the space SP2 in which the vacuum region VSP is not formed may be, for example, a space in which a relatively large number of gas molecules are present so as to hinder the appropriate irradiation of the sample W of the electron beam EB. For example, the pressure in the space SP2 may be, for example, a pressure of 1 × 10 ⁻² pascal or more. Typically, the space SP2 may be an atmospheric pressure space. In this way, the spaces SP1 and SP2 may be distinguished from their pressure (that is, atmospheric pressure).

In order to form such a vacuum region VSP by the differential exhaust, in the example shown in FIG. 2, the differential exhaust system 12 includes the vacuum forming member 121, the vacuum forming member 122, the vacuum forming member 123, and the vacuum forming. It includes a member 124. Further, the vacuum forming member 124 includes a vacuum forming member 1241, a vacuum forming member 1242, and a vacuum forming member 1243. However, the differential exhaust system 12 may have any structure as long as the vacuum region VSP can be formed.

As shown in FIG. 2, the differential exhaust system 12 is formed with an opening 126 facing the beam passing space SPb2. A pipe 127 is connected to the opening 126. The opening 126 and the pipe 127 will be described in detail when the structure of the differential exhaust system 12 is described (see FIGS. 3 and 4), and thus detailed description thereof will be omitted here.

(1-3) Structure of Differential Exhaust System 12 Subsequently, the structure of the differential exhaust system 12 will be described in more detail with reference to FIGS. 3 to 5. FIG. 3 is a cross-sectional view showing the structure of the differential exhaust system 12 of the first embodiment. FIG. 4 is a perspective view showing the structure of the differential exhaust system 12 of the first embodiment in a state where the vacuum forming member 121 and the vacuum forming member 124 are separated along the Z-axis direction. FIG. 5 is a plan view showing the shape of the injection surface 12LS of the differential exhaust system 12.

As shown in FIGS. 3 and 4, the vacuum forming member 121 is a tubular member extending downward from the beam optical system 11. The vacuum forming member 121 is arranged below the beam optical system 11 (that is, on the −Z side). The vacuum forming member 121 is connected to the beam optical system 11 below the beam optical system 11. For example, the vacuum forming member 121 may be connected to the beam optical system 11 so that the upper surface 121Su of the vacuum forming member 121 is connected to the lower surface of the beam optical system 11. The vacuum forming member 121 may be integrated with the beam optical system 11 or may be separable from the beam optical system 11.

Inside the vacuum forming member 121, a beam passing space SPb2-1 forming a part of the beam passing space SPb2 is formed. The beam passage space SPb2-1 penetrates the vacuum forming member 121. In the example shown in FIGS. 3 and 4, the beam passage space SPb2-1 penetrates the vacuum forming member 121 from the lower surface 121Sl of the vacuum forming member 121 toward the upper surface 121Su of the vacuum forming member 121. The beam passing space SPb2-1 is a beam of the beam optical system 11 via one end of the beam passing space SPb2-1 (in FIG. 4, the end on the + Z side and the opening formed in the upper surface 121Su). It is connected to the passage space SPb1 (see FIG. 2). The beam passing space SP2-1 further passes through the other end of the beam passing space SPb2-1 (in FIG. 3, the end on the −Z side and the opening formed in the lower surface 121Sl), and the vacuum forming member 121 It is connected to the external space (more specifically, the beam passing space SPb2-2 of the vacuum forming member 122 described later).

The vacuum forming member 121 is further formed with an exhaust passage EP1-1 forming a part of the exhaust passage EP1 and an exhaust passage EP2-1 forming a part of the exhaust passage EP2. The exhaust passages EP1-1 to EP2-1 are passages (that is, spaces) separated from each other. The exhaust passages EP1-1 to EP2-1 are passages separated from the beam passage space SPb2-1. Each of the exhaust passages EP1-1 to EP2-1 penetrates the vacuum forming member 121 from the lower surface 121Sl of the vacuum forming member 121 toward the other surface (side surface in the example shown in FIG. 3) of the vacuum forming member 121. There is. Therefore, each of the exhaust passages EP1-1 to EP2-1 may include a passage portion extending along the Z axis and a passage portion extending along the direction intersecting the Z axis. Each of the exhaust passages EP1-1 to EP2-1 has one end of each of the exhaust passages EP1-1 to EP2-1 (in the example shown in FIG. 3, an opening formed on the side surface of the vacuum forming member 121). It is connected to the vacuum pump 52 via. Each of the exhaust passages EP1-1 to EP2-1 further passes through the other end of each of the exhaust passages EP1-1 to EP2-1 (in the example shown in FIG. 5, an opening formed in the lower surface 121Sl). It is connected to the space outside the vacuum forming member 121 (more specifically, the exhaust passages EP1-2 to EP2-2 formed in the vacuum forming member 122 described later).

The vacuum forming member 122 is a member extending downward from the vacuum forming member 121. The vacuum forming member 122 is arranged below the vacuum forming member 121 (that is, on the −Z side). The vacuum forming member 122 is connected to the vacuum forming member 121 below the vacuum forming member 121. For example, the vacuum forming member 122 may be connected to the vacuum forming member 121 so that the upper surface 122Su of the vacuum forming member 122 is connected to the lower surface 121Sl of the vacuum forming member 121. The vacuum forming member 122 may be integrated with the vacuum forming member 121 or may be separable from the vacuum forming member 121.

Inside the vacuum forming member 122, a beam passing space SPb2-2 forming a part of the beam passing space SPb2 is formed. The beam passage space SPb2-2 penetrates the vacuum forming member 122. In the example shown in FIG. 3, the beam passage space SPb2-2 penetrates the vacuum forming member 122 from the lower surface 122Sl of the vacuum forming member 122 toward the upper surface 122Su of the vacuum forming member 122. The beam passing space SPb2-2 is a vacuum forming member via one end of the beam passing space SPb2-2 (in the example shown in FIG. 3, the end on the + Z side and the opening formed in the upper surface 122Su). It is connected to the beam passage space SPb2-1 of 121. The beam passage space SP2-2 is further evacuated through the other end of the beam passage space SPb2-2 (in the example shown in FIG. 3, the end on the −Z side, which is an opening formed in the lower surface 122Sl). It is connected to the space outside the forming member 122 (more specifically, the beam passing space SPb2-3 of the vacuum forming member 123 described later).

The vacuum forming member 122 is further formed with an exhaust passage EP1-2 forming a part of the exhaust passage EP1. The exhaust passage EP1-2 is connected to the exhaust passage EP1-1 of the vacuum forming member 121 via one end of the exhaust passage EP1-2 (in the example shown in FIG. 3, an opening formed in the upper surface 122Su). ing. The exhaust passage EP1-2 is a space (more specifically) outside the vacuum forming member 122 via the other end of the exhaust passage EP1-2 (in the example shown in FIG. 3, an opening formed in the lower surface 122Sl). Is connected to the exhaust passage EP1-3) formed in the vacuum forming member 123 described later.

The vacuum forming member 122 is further formed with an exhaust passage EP2-2 forming a part of the exhaust passage EP2. The exhaust passage EP2-2 is connected to the exhaust passage EP2-1 of the vacuum forming member 121 via one end of the exhaust passage EP2-2 (in the example shown in FIG. 3, an opening formed in the upper surface 122Su). ing. The exhaust passage EP2-2 is a space (more specifically) outside the vacuum forming member 122 via the other end of the exhaust passage EP2-2 (in the example shown in FIG. 3, an opening formed in the lower surface 122Sl). Is connected to the exhaust passage EP2-3) formed in the vacuum forming member 123 described later.

The vacuum forming member 123 is a member extending downward from the vacuum forming member 122. The vacuum forming member 123 is arranged below the vacuum forming member 122 (that is, on the −Z side). The vacuum forming member 123 is connected to the vacuum forming member 122 below the vacuum forming member 122. For example, the vacuum forming member 123 may be connected to the vacuum forming member 122 so that the upper surface 123Su of the vacuum forming member 123 is connected to the lower surface 122Sl of the vacuum forming member 122. The vacuum forming member 123 may be integrated with the vacuum forming member 122 or may be separable from the vacuum forming member 122.

Inside the vacuum forming member 123, a beam passing space SPb2-3 forming a part of the beam passing space SPb2 is formed. The beam passage space SPb2-3 penetrates the vacuum forming member 123. In the example shown in FIG. 3, the beam passage space SPb2-3 penetrates the vacuum forming member 123 from the lower surface 123Sl of the vacuum forming member 123 toward the upper surface 123Su of the vacuum forming member 123. The beam passing space SPb2-3 is a vacuum forming member via one end of the beam passing space SPb2-3 (in the example shown in FIG. 3, the end on the + Z side and the opening formed in the upper surface 123Su). It is connected to the beam passage space SPb2-2 of 122. The beam passage space SP2-3 is further evacuated through the other end of the beam passage space SPb2-3 (in the example shown in FIG. 3, the end on the −Z side, which is an opening formed in the lower surface 123Sl). It is connected to the space outside the forming member 123 (more specifically, the beam passing space SPb2-4 of the vacuum forming member 124 described later).

The vacuum forming member 123 is further formed with an exhaust passage EP1-3 forming a part of the exhaust passage EP1. The exhaust passage EP1-3 is connected to the exhaust passage EP1-2 of the vacuum forming member 122 via one end of the exhaust passage EP1-3 (in the example shown in FIG. 3, an opening formed in the upper surface 123Su). ing. The exhaust passage EP1-3 is a space (more specifically) outside the vacuum forming member 123 via the other end of the exhaust passage EP1-3 (in the example shown in FIG. 3, an opening formed in the lower surface 123Sl). Is connected to the exhaust passage EP1-4) formed in the vacuum forming member 124 described later.

The vacuum forming member 123 is further formed with an exhaust passage EP2-3 forming a part of the exhaust passage EP2. The exhaust passage EP2-3 is connected to the exhaust passage EP2-2 of the vacuum forming member 122 via one end of the exhaust passage EP2-3 (in the example shown in FIG. 3, an opening formed in the upper surface 123Su). ing. The exhaust passage EP2-3 is a space (more specifically) outside the vacuum forming member 123 via the other end of the exhaust passage EP2-3 (in the example shown in FIG. 3, an opening formed in the lower surface 123Sl). Is connected to the exhaust passage EP2-4) formed in the vacuum forming member 124 described later.

The vacuum forming member 124 is a member extending downward from the vacuum forming member 123. The vacuum forming member 124 is arranged below the vacuum forming member 123 (that is, on the −Z side). The vacuum forming member 124 is connected to the vacuum forming member 123 below the vacuum forming member 123. For example, the vacuum forming member 124 may be connected to the vacuum forming member 123 so that the upper surface 124Su of the vacuum forming member 124 is connected to the lower surface 123Sl of the vacuum forming member 123. The vacuum forming member 124 may be integrated with the vacuum forming member 123 or may be separable from the vacuum forming member 123.

As described above, the vacuum forming member 124 includes the vacuum forming members 1241 to 1243. Each of the vacuum forming members 1241 to 1243 is arranged below the vacuum forming member 123 (that is, on the −Z side). Each of the vacuum forming members 1241 to 1243 is connected to the vacuum forming member 123 below the vacuum forming member 123. For example, each of the vacuum forming members 1241 to 1243 may be connected to the vacuum forming member 123 so that the upper surface of each of the vacuum forming members 1241 to 1243 is connected to the lower surface 123Sl of the vacuum forming member 123. Each of the vacuum forming members 1241 to 1243 may be integrated with the vacuum forming member 123 or may be separable from the vacuum forming member 123.

The vacuum forming member 124 has a structure in which the vacuum forming members 1241 to 1243 are laminated with a gap secured between them. The vacuum forming member 124 may have a structure in which the vacuum forming members 1241 to 1243 are laminated in a nested manner. In the "structure in which the vacuum forming members 1241 to 1243 are laminated in a nested manner (in other words, incorporated)" in the first embodiment, the vacuum forming members 1241 to 1243 having the same shape as each other are laminated. It also includes a structure in which at least two vacuum forming members 1241 to 1243 having different shapes are laminated.

Inside the vacuum forming member 1241, a beam passing space SPb2-4 forming a part of the beam passing space SPb2 is formed. The beam passage space SPb2-4 penetrates the vacuum forming member 1241. In the example shown in FIG. 3, the beam passage space SPb2-4 faces from the lower surface of the vacuum forming member 1241 (that is, at least a part of the injection surface 12LS) to the upper surface of the vacuum forming member 1241 (that is, a part of the upper surface 124Su). It penetrates the vacuum forming member 1241. The beam passing space SPb2-4 is via one end of the beam passing space SPb2-4 (in the example shown in FIG. 3, the end on the + Z side, which is an opening formed on the upper surface of the vacuum forming member 1241). , It is connected to the beam passage space SPb2-3 of the vacuum forming member 123. The beam passing space SP2-4 is further the other end of the beam passing space SPb2-4 (in the example shown in FIG. 3, the end on the −Z side, and the beam ejection port formed on the lower surface of the vacuum forming member 1241. It is connected to the space outside the vacuum forming member 1241 (more specifically, the beam passing space SPb3) via 1250).

The vacuum forming member 1241 is located between the sample W and the electron detector 117 from the sample W in the Z-axis direction (or any direction in which at least a part of the beam passing space SPb2 intersects the surface WSu of the sample W). It has a shape that can realize a state in which the charged particles of the sample WSu spread away from the irradiated position in at least one of the X-axis direction and the Y-axis direction (or the direction along the surface WSu of the sample W) as the distance increases. You may be doing it. That is, between the sample W and the electron detector 117, the inner wall surface of the vacuum forming member 1241 that defines the beam passage space SPb2 is a sample in the Z-axis direction (or any direction that intersects the surface WSu of the sample W). It may have a shape that expands away from the optical axis AX of the beam optical system 11 with respect to at least one of the X-axis direction and the Y-axis direction (or the direction along the surface WSu of the sample W) as the distance from W increases. ..

The vacuum forming member 1242 and the vacuum forming member 1241 form an exhaust passage EP1-4 forming a part of the exhaust passage EP1. Specifically, in the vacuum forming member 1242, the inner surface of the vacuum forming member 1242 is the vacuum forming member 1241 in a state where a gap is secured between the inner surface of the vacuum forming member 1242 and the outer surface of the vacuum forming member 1241. It is aligned with respect to the vacuum forming member 1241 so as to face the outer side surface. As a result, the gap between the inner surface of the vacuum forming member 1242 (that is, the surface facing the optical axis AX side) and the outer surface of the vacuum forming member 1241 (that is, the surface facing the opposite side of the optical axis AX). However, it can be used as an exhaust passage EP1-4. The exhaust passage EP1-4 is connected to the exhaust passage EP1-3 of the vacuum forming member 123 via one end of the exhaust passage EP1-4 (in the example shown in FIG. 3, an annular opening formed in the upper surface 124Su). You are connected. The exhaust passage EP1-4 is a space outside the vacuum forming member 124 via the other end of the exhaust passage EP1-4 (in the example shown in FIG. 3, the annular exhaust port 1251 formed on the injection surface 12LS). (More specifically, it is connected to the space between the differential exhaust system 12 and the surface WSu of the sample W).

The vacuum forming member 1243 and the vacuum forming member 1242 form an exhaust passage EP2-4 forming a part of the exhaust passage EP2. Specifically, in the vacuum forming member 1243, the inner surface of the vacuum forming member 1243 is the vacuum forming member 1242 in a state where a gap is secured between the inner surface of the vacuum forming member 1243 and the outer surface of the vacuum forming member 1242. It is aligned with respect to the vacuum forming member 1242 so as to face the outer side surface. As a result, the gap between the inner surface of the vacuum forming member 1243 and the outer surface of the vacuum forming member 1242 can be used as the exhaust passage EP2-4. The exhaust passage EP2-4 is connected to the exhaust passage EP2-3 of the vacuum forming member 123 via one end of the exhaust passage EP2-4 (in the example shown in FIG. 3, an annular opening formed in the upper surface 124Su). You are connected. The exhaust passage EP2-4 passes through the other end of the exhaust passage EP2-4 (in the example shown in FIG. 3, the exhaust port 1252 formed on the injection surface 12LS), and the space outside the vacuum forming member 124 (more than that). Specifically, it is connected to the space between the differential exhaust system 12 and the surface WSu of the sample W).

As shown in FIG. 5, the injection surface 12LS includes an injection surface 121LS having a circular shape in the plane along the XY plane. Further, as shown in FIG. 5, the injection surface 12LS protrudes outward from the injection surface 121LS along one direction along the XY plane (in the example shown in FIG. 5, the direction toward the + Y side). The surface 122LS may be included. However, the shape of the injection surface 12LS is not limited to the shape shown in FIG. 5, and may be any other shape (for example, rectangular or elliptical shape).

Each of the vacuum forming members 1241 to 1243 may have any shape as long as the beam passage space SPb2-4 and the exhaust passages EP1-4 to EP2-4 can be formed. The vacuum forming member 124 may have any shape as long as the beam passage space SPb2-4 and the exhaust passages EP1-4 to EP3-4 can be formed. The vacuum forming member 124 does not have to be separated into a plurality of vacuum forming members 1241 to 1243 as long as the beam passage space SPb2-4 and the exhaust passages EP1-4 to EP2-4 can be formed.

In the first embodiment, as shown in FIGS. 3 and 4 (further, FIG. 2), the differential exhaust system 12 is further formed with an opening 126. 2 to 4 show an example in which the opening 126 is formed in the vacuum forming member 121, but the opening 126 is at least one of the vacuum forming members 122 to 124 in addition to or in place of the vacuum forming member 121. It may be formed in. The opening 126 is formed so as to face the beam passage space SPb2. The opening 126 is formed so as to connect to the beam passage space SPb2. The opening 126 is formed above the beam ejection port 1250 (that is, opposite to the sample W) that defines the lower boundary (ie, the end) of the beam passage space SPb2. The opening 126 is formed below the opening 120 (that is, on the same side as the sample W) that defines the upper boundary (that is, the end) of the beam passage space SPb2. The opening 126 is formed in a portion of the vacuum forming member 121 facing the beam passing space SPb2. For example, the opening 126 is formed in the inner wall of the vacuum forming member 121 that defines the beam passage space SPb2.

A pipe 127 penetrating the vacuum forming member 121 is connected to the opening 126. Therefore, the pipe 127 is connected to the beam passage space SPb2 via the opening 126. As shown in FIG. 1, a gas supply device 6 is connected to the pipe 127 via a valve 1281 and a pipe 1291. Further, as shown in FIG. 1, the exhaust device 7 is connected to the pipe 127 via the valve 1282 and the pipe 1292. Each of the

valves

1281 and 1282 is a needle valve, but other types of valves may be used.

The gas supply device 6 can supply gas to at least a part of the beam passage space SPb2 via the pipe 1291, the valve 1281, the pipe 127, and the opening 126 under the control of the control device 4. That is, the gas supply device 6 can supply air to at least a part of the beam passage space SPb2 through the pipe 1291, the valve 1281, the pipe 127, and the opening 126 under the control of the control device 4. Specifically, when the valve 1281 is in the closed state, the gas supply device 6 cannot supply gas to at least a part of the beam passage space SPb2. On the other hand, when the valve 1281 is in the open state, the gas supply device 6 can supply gas to at least a part of the beam passage space SPb2. Therefore, the state of the gas supply device 6 is a state in which gas is supplied to at least a part of the beam passage space SPb2 by switching the state of the valve 1281 under the control of the control device 4, and at least one of the beam passage space SPb2. It can be switched between the state where gas is not supplied to the part. As a result, the gas supply device 6 can supply gas to at least a part of the beam passage space SPb2 at a desired timing.

When gas is supplied to at least a part of the beam passing space SPb2, the pressure (that is, atmospheric pressure) of at least a part of the beam passing space SPb2 changes. That is, when gas is supplied to at least a part of the beam passing space SPb2, the degree of vacuum of at least a part of the beam passing space SPb2 changes. Therefore, the gas supply device 6 supplies a desired flow rate of gas to at least a part of the beam passage space SPb2 through the opening 126 under the control of the control device 4, and vacuums at least a part of the beam passage space SPb2. The degree can be controlled. The gas supply device 6 controls the flow rate of the gas supplied from the gas supply device 6 to at least a part of the beam passage space SPb2 by controlling the flow rate of the gas supplied by the gas supply device 6 to the pipe 1291. You may. Alternatively, the flow rate of the gas supplied from the gas supply device 6 to at least a part of the beam passage space SPb2 also depends on the opening degree of the valve 1281. This is because the larger the opening degree of the valve 1281, the larger the flow rate of the gas supplied from the pipe 1291 to the pipe 127 (furthermore, the beam passing space SPb2) via the valve 1281. Therefore, the control device 4 may control the flow rate of the gas supplied from the gas supply device 6 to at least a part of the beam passage space SPb2 by controlling the opening degree of the valve 1281. In this case, each of the gas supply device 7 and the valve 1281 can substantially function as a device capable of controlling the degree of vacuum of at least a part of the beam passage space SPb2.

Since the beam passing space SPb2 is connected to the beam passing space SPb1, the gas supply device 6 may be able to supply gas to at least a part of the beam passing space SPb1 via the beam passing space SPb2. In this case, the gas supply device 6 may supply gas to at least a part of the beam passing space SPb1 to control the degree of vacuum of at least a part of the beam passing space SPb1. Further, since the beam passing space SPb2 is connected to the beam passing space SPb3, the gas supply device 6 may be able to supply gas to at least a part of the beam passing space SPb3 via the beam passing space SPb2. .. In this case, the gas supply device 6 may supply gas to at least a part of the beam passing space SPb3 to control the degree of vacuum of at least a part of the beam passing space SPb3.

In this way, under the control of the control device 4, the gas supply device 6 supplies gas to at least a part of the beam passage space SPb including the beam passage space SPb1 to SPb3 through the opening 126, and the beam passage space SPb. At least a part of the degree of vacuum can be controlled.

The gas supplied by the gas supply device 6 is not limited, but may include, for example, an inert gas. As an example of the inert gas, a rare gas (for example, at least one of helium gas, neon gas and argon gas) can be mentioned. Another example of the inert gas is nitrogen gas. The gas supplied by the gas supply device 6 may include, for example, a dehumidified gas. For example, the gas supplied by the gas supply device 6 may include a dehumidified inert gas. Alternatively, for example, the gas supplied by the gas supply device 6 may contain clean dry air (CDA: Clean Dry Air).

As shown in FIG. 1, the gas supply device 6 may supply gas to the beam passage space SPb via the filter 61. The filter 61 may be arranged in the pipe 1291, for example. That is, the pipe 1291 may include the filter 61. The filter 61 may be configured to be able to filter the gas passing through the filter 61. The filter 61 may be configured to be able to adsorb impurities contained in the gas passing through the filter 61. As an example of the filter 61, at least one of a HEPA (High Effectivey Particulate Air) filter, a ULPA (Ultra Low Particulate Air) filter, and a chemical filter can be mentioned. Examples of impurities include at least one of fine particles (fine particles, particles), an organic gas (organic gas), an alkaline gas (alkaline gas), and an acidic gas (acidic gas). As a result, the gas supply device 6 can supply the gas filtered by the filter 61 from which impurities have been removed to the beam passing space SPb. However, the scanning electron microscope SEMa does not have to include the filter 61. The filter 61 may be a selection filter that selectively passes a specific gas molecule.

A fine particle counter (particle counter) for detecting fine particles (particles) contained in the gas passing through the pipe 1291 may be arranged in the pipe 1291.

At least one of a hygrometer and a dew point meter for determining the humidity of the gas passing through the pipe 1291 may be arranged in the pipe 1291. The dew point meter determines the humidity by measuring the dew point temperature. A hygroscopic agent may be arranged in the pipe 1291.

Under the control of the control device 4, the exhaust device 7 can exhaust at least a part of the beam passage space SPb2 via the pipe 1292, the valve 1282, the pipe 127, and the opening 126. Specifically, when the valve 1282 is in the closed state, the exhaust device 7 cannot exhaust at least a part of the beam passage space SPb2. On the other hand, when the valve 1282 is in the open state, the exhaust device 6 can exhaust at least a part of the beam passage space SPb2. Therefore, the state of the exhaust device 7 is a state in which at least a part of the beam passing space SPb2 is exhausted and at least a part of the beam passing space SPb2 is exhausted by switching the state of the valve 1282 under the control of the control device 4. It can be switched between the non-state and the non-state. As a result, the exhaust device 7 can exhaust at least a part of the beam passing space SPb2 at a desired timing.

The pipe 1292 passes through a filter for filtering the gas passing through the pipe 1292, a hygrometer for absorbing the moisture of the gas passing through the pipe 1292, a fine particle meter for detecting fine particles contained in the gas passing through the pipe 1292, and the pipe 1292. At least one of a hygrometer and a dew point meter for determining the humidity of the gas may be arranged.

At least one of a gas analyzer and a mass spectrometer for analyzing substances passing through the pipe 1292 may be arranged in the pipe 1292. Examples of the mass spectrometer include a quadrupole mass spectrometer (Q-mass: Quadrupole mass spectrometer).

When at least a part of the beam passing space SPb2 is exhausted, the pressure (that is, atmospheric pressure) of at least a part of the beam passing space SPb2 changes. That is, when at least a part of the beam passing space SPb2 is exhausted, the degree of vacuum of at least a part of the beam passing space SPb2 changes. Therefore, under the control of the control device 4, the exhaust device 7 exhausts at least a part of the beam passing space SPb2 through the opening 126 at a desired exhaust rate (that is, at least a part of the beam passing space SPb2). The degree of vacuum of at least a part of the beam passage space SPb2 can be controlled by recovering the gas at a desired flow rate). The exhaust device 7 controls the flow rate of the gas recovered from at least a part of the beam passage space SPb2 by controlling the exhaust speed of the exhaust device 7 itself (that is, the flow rate of the gas recovered by the exhaust device 7). You may. Alternatively, the flow rate of the gas recovered from at least a part of the beam passage space SPb2 also depends on the opening degree of the valve 1282. This is because the larger the opening degree of the valve 1282, the larger the flow rate of the gas recovered by the exhaust device 7 via the valve 1282. Therefore, the control device 4 may control the flow rate of the gas recovered from at least a part of the beam passing space SPb2 by controlling the opening degree of the valve 1282. In this case, each of the exhaust device 7 and the valve 1282 can substantially function as a device capable of controlling the degree of vacuum of at least a part of the beam passing space SPb2.

Since the beam passing space SPb2 is connected to the beam passing space SPb1, the exhaust device 7 may be able to exhaust at least a part of the beam passing space SPb1 via the beam passing space SPb2. In this case, the exhaust device 7 may be able to exhaust at least a part of the beam passing space SPb1 and control the degree of vacuum of at least a part of the beam passing space SPb1. Further, since the beam passing space SPb2 is connected to the beam passing space SPb3, the exhaust device 7 may be able to exhaust at least a part of the beam passing space SPb3 via the beam passing space SPb2. In this case, the exhaust device 7 may be able to exhaust at least a part of the beam passing space SPb3 and control the degree of vacuum of at least a part of the beam passing space SPb3.

In this way, under the control of the control device 4, the exhaust device 7 exhausts at least a part of the beam passing space SPb through the opening 126 to control the degree of vacuum of at least a part of the beam passing space SPb. Can be done.

The exhaust device 7 may include a vacuum pump. In this case, the exhaust capacity of the vacuum pump included in the exhaust device 7 may be the same as the exhaust capacity of the above-mentioned vacuum pump 51 used for exhausting SPb3 from the beam passing space SPb1. Alternatively, the exhaust capacity of the vacuum pump included in the exhaust device 7 may be lower or higher than the exhaust capacity of the vacuum pump 51.

(1-2) Control operation of the degree of vacuum of at least a part of the beam passing space SPb Subsequently, referring to FIGS. 6 to 9, air is supplied to at least a part of the beam passing space SPb through the opening 126. The operation of controlling the degree of vacuum of at least a part of the beam passing space SPb by exhausting at least a part of the beam passing space SPb at and / or through the opening 126 will be further described. Each of FIGS. 6 and 7 is a cross-sectional view showing how the gas supply device 6 supplies air to at least a part of the beam passage space SPb (particularly, the beam passage space SPb2). 8 and 9 are cross-sectional views showing how the exhaust device 7 exhausts at least a part of the beam passing space SPb (particularly, the beam passing space SPb2).

As described above, when gas is supplied to at least a part of the beam passing space SPb by the gas supply device 6, the pressure of at least a part of the beam passing space SPb changes. More specifically, the pressure of at least a part of the beam passing space SPb increases. Therefore, when gas is supplied to at least a part of the beam passing space SPb, the degree of vacuum of at least a part of the beam passing space SPb decreases. Therefore, the gas supply device 6 can function as a device capable of controlling the vacuum degree of at least a part of the beam passing space SPb so that the vacuum degree of at least a part of the beam passing space SPb is reduced. In this case, the gas supply device 6 supplies gas to at least a part of the beam passing space SPb at a timing when it is desired to reduce the degree of vacuum of at least a part of the beam passing space SPb.

As the amount of gas supplied by the gas supply device 6 to at least a part of the beam passing space SPb increases, the amount of increase in the pressure of at least a part of the beam passing space SPb increases. That is, as the amount of gas supplied by the gas supply device 6 to at least a part of the beam passing space SPb increases, the amount of decrease in the degree of vacuum of at least a part of the beam passing space SPb increases. On the contrary, as the amount of gas supplied by the gas supply device 6 to at least a part of the beam passing space SPb decreases, the amount of increase in the pressure of at least a part of the beam passing space SPb becomes smaller. That is, as the amount of gas supplied by the gas supply device 6 to at least a part of the beam passing space SPb decreases, the amount of decrease in the degree of vacuum of at least a part of the beam passing space SPb becomes smaller. Therefore, the gas supply device 6 may supply a desired flow rate of gas to at least a part of the beam passing space SPb so that the vacuum degree of at least a part of the beam passing space SPb becomes a desired vacuum degree.

However, when the degree of vacuum of at least a part of the beam passing space SPb decreases due to the supply of gas from the gas supply device 6 to at least a part of the beam passing space SPb, the beam irradiation device 1 and the sample W The degree of vacuum of at least a part of the beam passing space SPb3 formed in the intervening space may also be reduced. When the degree of vacuum of at least a part of the beam passing space SPb3 is reduced, the negative pressure acting on the beam irradiation device 1 (particularly the injection surface 12LS) and the sample W (particularly the surface WSu) from the beam passing space SPb3 may be reduced. There is. That is, the force acting on the beam irradiation device 1 from the beam passing space SPb3 so as to bring the beam irradiation device 1 closer to the sample W and the force acting on the sample W from the beam passing space SPb3 so as to bring the sample W closer to the beam irradiation device 1. May decrease. In this case, the beam irradiation device 1 and the sample W may be separated from each other. As a result, the distance D between the beam irradiation device 1 and the sample W may deviate from the desired distance D_target. Typically, the distance D between the beam irradiator 1 and the sample W may be larger than the desired distance D_taget.

Therefore, in the first embodiment, the control device 4 may control the interval D during at least a part of the period in which the gas supply device 6 supplies the gas to at least a part of the beam passing space SPb. That is, the control device 4 may control the degree of vacuum of at least a part of the beam passing space SPb by using the gas supply device 6 and also control the interval D. In this case, the control device 4 may control the interval D in parallel with controlling the degree of vacuum of at least a part of the beam passing space SPb by using the gas supply device 6.

The control device 4 includes the interval adjusting system 14 and the stage so that the interval D is maintained as the desired interval D_target during at least a part of the period in which the gas supply device 6 supplies gas to at least a part of the beam passage space SPb. At least one of the drive system 23 may be controlled. The control device 4 has both a period before the gas supply device 6 supplies gas to at least a part of the beam passage space SPb and a period after the gas supply device 6 supplies gas to at least a part of the beam passage space SPb. In, at least one of the interval adjusting system 14 and the stage drive system 23 may be controlled so that the interval D is maintained as the desired interval D_taget.

For example, as shown in FIG. 6, the flange member 13 applies a force (for example, a force capable of moving the flange member 13 to the + Z side) that acts to separate the beam irradiation device 1 and the sample W in the Z-axis direction. When the interval adjusting system 14 adjusts the interval D by applying the gas to, the control device 4 adjusts the interval as compared with before the gas supply device 6 supplies gas to at least a part of the beam passage space SPb. The interval adjusting system 14 may be controlled so that the force applied to the flange member 13 from the adjusting system 14 is reduced. For example, as shown in FIG. 6, a force acting to separate the beam irradiation device 1 and the sample W in the Z-axis direction (for example, a force capable of moving the stage 22 to the −Z side) is applied to the stage 22. When the stage drive system 23 adjusts the interval D by applying the gas, the control device 4 drives the stage as compared with before the gas supply device 6 supplies gas to at least a part of the beam passage space SPb. The stage drive system 23 may be controlled so that the force applied to the stage 22 from the system 23 is reduced. In this case, the beam irradiation device 1 and the sample W are separated from each other due to the gas supply device 6 supplying gas to at least a part of the beam passage space SPb. The force applied to the interval adjusting system 14 and / or the stage drive system 23 so as to separate from W is reduced. Therefore, as compared with the case where the force applied to the interval adjusting system 14 and / or the stage drive system 23 does not decrease so as to separate the beam irradiation device 1 and the sample W, the beam irradiation device 1 and the sample W are separated from each other. It becomes difficult to separate (that is, the amount of increase in the interval D becomes small). In particular, if the amount of reduction in the force applied by the interval adjusting system 14 and / or the stage drive system 23 is set to an appropriate amount capable of maintaining the interval D as the desired interval D_target, the beam irradiation device. 1 and the sample W are not separated from each other (that is, the interval D is not increased). Therefore, the control device 4 may reduce the force applied to the interval adjusting system 14 and / or the stage drive system 23 by a desired amount so that the interval D is maintained as the desired interval D_taget.

Alternatively, for example, as shown in FIG. 7, a force acting to bring the beam irradiation device 1 and the sample W closer to each other in the Z-axis direction (for example, a force capable of moving the flange member 13 to the −Z side) is applied. When the interval adjusting system 14 adjusts the interval D by applying it to the flange member 13, the control device 4 compares with the gas supply device 6 before supplying gas to at least a part of the beam passage space SPb. The spacing adjusting system 14 may be controlled so that the force applied to the flange member 13 from the spacing adjusting system 14 is increased. For example, as shown in FIG. 7, a force acting to bring the beam irradiation device 1 and the sample W closer to each other in the Z-axis direction (for example, a force capable of moving the stage 22 to the + Z side) is applied to the stage 22. When the stage drive system 23 adjusts the interval D by doing so, the control device 4 compares with the stage drive system before the gas supply device 6 supplies gas to at least a part of the beam passage space SPb. The stage drive system 23 may be controlled so that the force applied to the stage 22 from the 23 increases. In this case, the beam irradiation device 1 and the sample W may be separated from each other due to the gas supply device 6 supplying gas to at least a part of the beam passage space SPb. The force applied to the interval adjusting system 14 and / or the stage drive system 23 increases so as to bring it closer to W. Therefore, the beam irradiating device 1 and the sample W are compared with the case where the force applied to the interval adjusting system 14 and / or the stage driving system 23 is not increased so that the beam irradiating device 1 and the sample W are brought closer to each other. It becomes difficult to separate (that is, the amount of increase in the interval D becomes small). In particular, if the amount of increase in the force applied by the interval adjusting system 14 and / or the stage drive system 23 is set to an appropriate amount capable of maintaining the interval D as the desired interval D_target, the beam irradiation device. 1 and sample W do not separate (that is, the interval D does not increase). Therefore, the control device 4 may increase the force applied to the interval adjusting system 14 and / or the stage drive system 23 by a desired amount so that the interval D is maintained as the desired interval D_taget.

However, the control device 4 may allow a temporary increase in the interval D due to the gas supply device 6 supplying gas to at least a part of the beam passage space SPb. That is, the control device 4 may allow the beam irradiation device 1 and the sample W to be temporarily separated from each other due to the gas supply device 6 supplying gas to at least a part of the beam passage space SPb. .. In this case, the control device 4 may control at least one of the interval adjusting system 14 and the stage drive system 23 so as to decrease the temporarily increased interval D and return it to the desired interval D_target. That is, the control device 4 may control at least one of the interval adjusting system 14 and the stage drive system 23 so that the beam irradiation device 1 temporarily separated and the sample W come close to each other again. Even in this case, there is no problem as long as the temporary increase in the interval D does not affect the measurement by the scanning electron microscope SEMa.

On the other hand, as described above, when at least a part of the beam passing space SPb is exhausted by the exhaust device 7, the pressure of at least a part of the beam passing space SPb changes. More specifically, the pressure of at least a part of the beam passage space SPb is reduced. Therefore, when at least a part of the beam passing space SPb is exhausted, the degree of vacuum of at least a part of the beam passing space SPb increases. Therefore, the exhaust device 7 can function as a device capable of controlling at least a part of the vacuum degree of the beam passing space SPb so that the degree of vacuum of at least a part of the beam passing space SPb increases. In this case, the exhaust device 7 exhausts at least a part of the beam passing space SPb at a timing when it is desired to increase the degree of vacuum of at least a part of the beam passing space SPb.

The more gas recovered from at least a part of the beam passing space SPb by the exhaust device 7, the greater the amount of pressure decrease in at least a part of the beam passing space SPb. That is, as the amount of gas recovered from at least a part of the beam passing space SPb by the exhaust device 7 increases, the amount of increase in the degree of vacuum of at least a part of the beam passing space SPb increases. On the contrary, as the amount of gas recovered from at least a part of the beam passing space SPb by the exhaust device 7 decreases, the amount of pressure decrease in at least a part of the beam passing space SPb becomes smaller. That is, as the amount of gas recovered from at least a part of the beam passing space SPb by the exhaust device 7 decreases, the amount of increase in the degree of vacuum of at least a part of the beam passing space SPb becomes smaller. Therefore, the exhaust device 7 may recover the gas from at least a part of the beam passing space SPb at a desired flow rate so that the degree of vacuum of at least a part of the beam passing space SPb becomes a desired degree of vacuum.

However, when the degree of vacuum of at least a part of the beam passing space SPb increases due to the exhaust device 7 exhausting at least a part of the beam passing space SPb, the space between the beam irradiating device 1 and the sample W becomes The degree of vacuum of at least a part of the beam passage space SPb3 formed may also increase. When the degree of vacuum of at least a part of the beam passing space SPb3 increases, the negative pressure acting on the beam irradiation device 1 (particularly the injection surface 12LS) and the sample W (particularly the surface WSu) from the beam passing space SPb3 may increase. There is. That is, the force acting on the beam irradiation device 1 from the beam passing space SPb3 so as to bring the beam irradiation device 1 closer to the sample W and the force acting on the sample W from the beam passing space SPb3 so as to bring the sample W closer to the beam irradiation device 1. May increase. In this case, the beam irradiation device 1 and the sample W may come close to each other. As a result, the distance D between the beam irradiation device 1 and the sample W may deviate from the desired distance D_target. Typically, the distance D between the beam irradiator 1 and the sample W may be smaller than the desired distance D_taget.

Therefore, in the first embodiment, the control device 4 may control the interval D during at least a part of the period in which the exhaust device 7 exhausts at least a part of the beam passing space SPb. That is, the control device 4 may use the exhaust device 7 to control the degree of vacuum of at least a part of the beam passing space SPb and also control the interval D. In this case, the control device 4 may control the interval D in parallel with controlling the degree of vacuum of at least a part of the beam passing space SPb by using the exhaust device 7.

The control device 4 has the interval adjusting system 14 and the stage drive system 23 so that the interval D is maintained as the desired interval D_target during at least a part of the period in which the exhaust device 7 exhausts at least a part of the beam passage space SPb. At least one of them may be controlled. The control device 4 desires an interval D both in the period before the exhaust device 7 exhausts at least a part of the beam passage space SPb and in the period after the exhaust device 7 exhausts at least a part of the beam passage space SPb. At least one of the interval adjustment system 14 and the stage drive system 23 may be controlled so that the interval D_target is maintained.

For example, as shown in FIG. 8, when the space adjusting system 14 adjusts the space D by applying a force acting to separate the beam irradiation device 1 and the sample W in the Z-axis direction to the flange member 13. In the control device 4, the interval adjustment system is provided so that the force applied to the flange member 13 from the interval adjustment system 14 increases as compared with before the exhaust device 7 exhausts at least a part of the beam passage space SPb. 14 may be controlled. For example, as shown in FIG. 8, when the stage drive system 23 adjusts the interval D by applying a force acting to separate the beam irradiation device 1 and the sample W in the Z-axis direction to the stage 22. The control device 4 sets the stage drive system 23 so that the force applied to the stage 22 from the stage drive system 23 increases as compared with before the exhaust device 7 exhausts at least a part of the beam passage space SPb. You may control it. In this case, the beam irradiation device 1 and the sample W are combined in a situation where the beam irradiation device 1 and the sample W may come close to each other due to the exhaust device 7 exhausting at least a part of the beam passage space SPb. The force applied to the interval adjusting system 14 and / or the stage drive system 23 increases so as to separate them. Therefore, as compared with the case where the force applied to the interval adjusting system 14 and / or the stage drive system 23 does not increase so as to separate the beam irradiation device 1 and the sample W, the beam irradiation device 1 and the sample W are separated from each other. It becomes difficult to approach (that is, the amount of decrease in the interval D becomes small). In particular, if the amount of increase in the force applied by the interval adjusting system 14 and / or the stage drive system 23 is set to an appropriate amount capable of maintaining the interval D as the desired interval D_target, the beam irradiation device. 1 and the sample W do not come close to each other (that is, the interval D does not decrease). Therefore, the control device 4 may increase the force applied to the interval adjusting system 14 and / or the stage drive system 23 by a desired amount so that the interval D is maintained as the desired interval D_taget.

Alternatively, for example, as shown in FIG. 9, the interval adjusting system 14 adjusts the interval D by applying a force acting to bring the beam irradiation device 1 and the sample W closer to each other in the Z-axis direction to the flange member 13. If so, the control device 4 is spaced so that the force applied to the flange member 13 by the spacing adjusting system 14 is reduced as compared to before the exhausting device 7 exhausts at least a part of the beam passage space SPb. The adjustment system 14 may be controlled. For example, as shown in FIG. 9, when the stage drive system 23 adjusts the interval D by applying a force acting to bring the beam irradiation device 1 and the sample W closer to each other in the Z-axis direction to the stage 22. The control device 4 sets the stage drive system 23 so that the force applied to the stage 22 from the stage drive system 23 is reduced as compared with before the exhaust device 7 exhausts at least a part of the beam passage space SPb. You may control it. In this case, the beam irradiation device 1 and the sample W are combined in a situation where the beam irradiation device 1 and the sample W may come close to each other due to the exhaust device 7 exhausting at least a part of the beam passage space SPb. The force applied to the interval adjusting system 14 and / or the stage drive system 23 is reduced so as to bring them closer to each other. Therefore, the beam irradiating device 1 and the sample W are compared with the case where the force applied by the interval adjusting system 14 and / or the stage driving system 23 is not reduced so that the beam irradiating device 1 and the sample W are brought closer to each other. It becomes difficult to approach (that is, the amount of decrease in the interval D becomes small). In particular, if the amount of reduction in the force applied by the interval adjusting system 14 and / or the stage drive system 23 is set to an appropriate amount capable of maintaining the interval D as the desired interval D_target, the beam irradiation device. 1 and the sample W do not come close to each other (that is, the interval D does not decrease). Therefore, the control device 4 may reduce the force applied to the interval adjusting system 14 and / or the stage drive system 23 by a desired amount so that the interval D is maintained as the desired interval D_taget.

However, the control device 4 may allow a temporary decrease in the interval D due to the exhaust device 7 exhausting at least a part of the beam passing space SPb. That is, the control device 4 may allow the beam irradiation device 1 and the sample W to temporarily approach each other due to the exhaust device 7 exhausting at least a part of the beam passing space SPb. In this case, the control device 4 may control at least one of the interval adjusting system 14 and the stage drive system 23 so as to increase the temporarily decreased interval D and return it to the desired interval D_target. That is, the control device 4 may control at least one of the interval adjusting system 14 and the stage drive system 23 so that the beam irradiation device 1 and the sample W that are temporarily approached are separated again. Even in this case, there is no problem as long as the temporary decrease in the interval D does not affect the measurement by the scanning electron microscope SEMa.

As described above, the scanning electron microscope SEMa can control the degree of vacuum of the beam passing space SPb by using the gas supply device 6 and / or the exhaust device 7. More specifically, the scanning electron microscope SEMa can control the degree of vacuum of the vacuum region VSP including at least a part of the beam passing space SPb by using the gas supply device 6 and / or the exhaust device 7. In this case, the control device 4 sets the operation mode of the scanning electron microscope SEMa to the first mode in which the vacuum region VSP (or at least a part of the beam passage space SPb, the same applies hereinafter) is used in the first pressure range and the vacuum. The region VSP may be switched between a second mode used in a second pressure range different from the first pressure range. More specifically, the control device 4 sets the operation mode of the scanning electron microscope SEMa to a pressure including the pressure in the first pressure range, and sets the pressure in the vacuum region VSP to the first mode. You may switch between the second mode and setting the pressure included in the pressure range of 2. That is, the control device 4 may switch the operation mode of the scanning electron microscope SEMa from either the first or second mode to the other of the first and second modes. In other words, the control device 4 may set the operation mode of the scanning electron microscope SEMa to the first mode or the second mode.

The control device 4 may switch the operation mode of the scanning electron microscope SEMa between the first mode and the second mode by using the opening 126 and the pipe 127. Specifically, the control device 4 uses the air supply and / or exhaust of the beam passage space SPb via the opening 126 and the pipe 127 to set the operation modes of the scanning electron microscope SEMa to the first mode and the second mode. You may switch between modes.

For example, the control device 4 controls (for example, changes) the flow rate of the gas supplied to the beam passage space SPb through the opening 126 and the pipe 127, thereby setting the operation mode of the scanning electron microscope SEMa to the first operation mode. You may switch between the mode and the second mode. Specifically, for example, the control device 4 is a scanning type by changing the flow rate of the gas supplied to the beam passing space SPb through the opening 126 and the pipe 127 from the first flow rate to the second flow rate. The operation mode of the electron microscope SEMa may be switched between the first mode and the second mode. For example, the control device 4 changes the flow rate of the gas supplied to the beam passage space SPb through the opening 126 and the pipe 127 from zero to more than zero or from more than zero to zero. The operation mode of the scanning electron microscope SEMa may be switched between the first mode and the second mode. In this case, typically, the flow rate of the gas supplied to the beam passage space SPb via the opening 126 and the pipe 127 in the first mode is sent to the beam passage space SPb via the opening 126 and the pipe 127 in the second mode. The flow rate is different from the flow rate of the supplied gas.

For example, the control device 4 controls (for example, changes) the flow rate of the gas recovered from the beam passing space SPb through the opening 126 and the pipe 127, thereby setting the operation mode of the scanning electron microscope SEMa to the first operation mode. You may switch between the mode and the second mode. Specifically, for example, the control device 4 is a scanning type by changing the flow rate of the gas recovered from the beam passing space SPb through the opening 126 and the pipe 127 from the third flow rate to the fourth flow rate. The operation mode of the electron microscope SEMa may be switched between the first mode and the second mode. For example, the control device 4 changes the flow rate of the gas recovered from the beam passage space SPb through the opening 126 and the pipe 127 from zero to more than zero or from more than zero to zero. The operation mode of the scanning electron microscope SEMa may be switched between the first mode and the second mode. In this case, typically, the flow rate of the gas recovered from the beam passage space SPb via the opening 126 and the pipe 127 in the first mode is from the beam passage space SPb via the opening 126 and the pipe 127 in the second mode. The flow rate is different from the flow rate of the recovered gas.

The control device 4 controls the flow rate of the gas recovered from the beam passage space SPb by the vacuum pump 52 via at least one of the exhaust passages EP1 and EP2 in addition to or in place of the opening 126 and the pipe 127 (eg, modification). By doing so, the operation mode of the scanning electron microscope SEMa may be switched between the first mode and the second mode. That is, the control device 4 controls (eg, changes) the flow rate of the gas recovered from the beam passage space SPb via at least one of the

exhaust ports

1251 and 1252 in addition to or in place of the opening 126 and the pipe 127. As a result, the operation mode of the scanning electron microscope SEMa may be switched between the first mode and the second mode. Specifically, for example, the control device 4 changes the flow rate of the gas recovered from the beam passage space SPb via at least one of the exhaust passages EP1 and EP2 from the fifth flow rate to the sixth flow rate. , The operation mode of the scanning electron microscope SEMa may be switched between the first mode and the second mode. For example, the control device 4 changes the flow rate of the gas recovered from the beam passage space SPb through at least one of the exhaust passages EP1 and EP2 from zero to more than zero or from more than zero to zero. As a result, the operation mode of the scanning electron microscope SEMa may be switched between the first mode and the second mode. In this case, typically, the flow rate of the gas recovered from the beam passage space SPb via at least one of the exhaust passages EP1 and EP2 in the first mode is via at least one of the exhaust passages EP1 and EP2 in the second mode. The flow rate is different from the flow rate of the gas recovered from the beam passage space SPb.

The control device 4 scans by controlling (for example, changing) the flow rate of the gas recovered from the beam passage space SPb by the vacuum pump 52 via the pipe 112 in addition to or in place of the opening 126 and the pipe 127. The operation mode of the type electron microscope SEMa may be switched between the first mode and the second mode. Specifically, the control device 4 controls (for example, changes) the flow rate of the gas recovered from the beam passage space SPb1 by the vacuum pump 52 via the pipe 112, so that the operation mode of the scanning electron microscope SEMa is changed. May be switched between the first mode and the second mode. The control device 4 controls (for example, changes) the flow rate of the gas recovered from the beam passage space SPb2 by the vacuum pump 52 via the pipe 112 and the beam passage space SPb1 to control (for example, change) the operation mode of the scanning electron microscope SEMa. May be switched between the first mode and the second mode. The control device 4 controls (for example, changes) the flow rate of the gas recovered from the beam passage space SPb3 by the vacuum pump 52 via the pipe 112 and the beam passage space SPb1 to SPb2, thereby causing the scanning electron microscope SEMa. The operation mode may be switched between the first mode and the second mode. In this case, for example, the control device 4 operates the scanning electron microscope SEMa by changing the flow rate of the gas recovered from the beam passing space SPb via the pipe 112 from the seventh flow rate to the eighth flow rate. The mode may be switched between the first mode and the second mode. For example, the control device 4 changes the flow rate of the gas recovered from the beam passage space SPb via the pipe 112 from zero to more than zero or from more than zero to zero, thereby scanning electrons. The operation mode of the microscope SEMa may be switched between the first mode and the second mode. In this case, typically, the flow rate of the gas recovered from the beam passing space SPb via the pipe 112 in the first mode is the flow rate of the gas recovered from the beam passing space SPb via the pipe 112 in the second mode. The flow rate will be different from.

Even when the operation mode of the scanning electron microscope SEMa is switched between the first mode and the second mode in this way, the control device 4 desires the distance D between the beam irradiation device 1 and the sample W. At least one of the interval adjusting system 14 and the stage drive system 23 may be controlled so that the interval D_target is maintained. That is, in the control device 4, the interval D when the operation mode of the scanning electron microscope SEMa is set to the first mode is the interval when the operation mode of the scanning electron microscope SEMa is set to the second mode. At least one of the interval adjustment system 14 and the stage drive system 23 may be controlled so as to be substantially the same as D. In the state of "the interval D in the first mode and the interval D in the second mode are almost the same" referred to here, the interval D in the first mode and the interval D in the second mode are literally exactly the same. The state in which the interval D in the first mode and the interval D in the second mode are different, but the two are different only to the extent that they do not interfere with the proper formation of the vacuum region VSP. Also includes. However, when the temporary increase or decrease of the interval D is allowed as described above, the control device 4 sets the interval D when the operation mode of the scanning electron microscope SEMa is set to the first mode. , At least one of the interval adjusting system 14 and the stage drive system 23 may be controlled so that the operation mode of the scanning electron microscope SEMa is different from the interval D when the operation mode is set to the second mode.

(1-3) Technical Effects of Scanning Electron Microscope SEMa of the First Embodiment As described above, in the scanning electron microscope SEMa of the first embodiment, an opening formed so as to face the beam passage space SPb. The degree of vacuum of at least a part of the beam passing space SPb can be controlled via 126. Therefore, the scanning electron microscope SEMa can control the degree of vacuum of at least a part of the beam passing space SPb without controlling the vacuum pump 51 mainly used for exhausting the entire beam passing space SPb. it can. In essence, the scanning electron microscope SEMa can locally control the degree of vacuum of a part of the beam passage space SPb without collectively controlling the degree of vacuum of the entire beam passage space SPb. Therefore, the scanning electron microscope SEMa has a partial vacuum degree of the beam passing space SPb (for example, an opening in the beam passing space SPb) as compared with the case where the entire vacuum degree of the beam passing space SPb is controlled collectively. The degree of vacuum of a local spatial portion located relatively close to 126) can be controlled (eg, changed) relatively quickly. For example, the scanning electron microscope SEMa can change the vacuum degree of at least a part of the beam passing space SPb2 and SPb3 relatively quickly without changing the vacuum degree of most of the beam passing space SPb1. For example, the scanning electron microscope SEMa is a space in the beam passing space SPb2 near the opening 126 while maintaining a relatively high degree of vacuum at the beam ejection port 1250 corresponding to the ends of the beam passing spaces SPb1 to SPb2. The degree of vacuum of the part can be changed relatively quickly. For example, in the scanning electron microscope SEMa, the degree of vacuum of the beam ejection port 1250 corresponding to the end of the beam passing space SPb1 to SPb2 is higher than the degree of vacuum of the space portion of the beam passing space SPb2 near the opening 126. , The electron beam EB can be applied to the sample W.

In this case, the scanning electron microscope SEMa may control at least a part of the vacuum degree of the beam passing space SPb (particularly, the vacuum degree of the beam passing space SPb3 facing the sample W) according to the characteristics of the sample W. Good. For example, in the scanning electron microscope SEMa, when the sample W is an insulator, the sample W is charged up due to the irradiation of the electron beam EB as compared with the case where the sample W is a non-insulator. Is relatively likely to occur. Here, insulating material, electric conductivity (conductivity) is low object, electrical conductivity consists of the following non-conductor 10 6 ^{S /} m. It cannot be said that this phenomenon of charge-up is preferable for the acquisition of an appropriate SEM image (or the acquisition of information on the sample W). Therefore, in the scanning electron microscope SEMa, when the sample W is an insulator, at least a part of the vacuum degree (particularly, the sample W) of the beam passing space SPb is compared with the case where the sample W is a non-insulator. The degree of vacuum of at least a part of the beam passing space SPb may be controlled so that the degree of vacuum of the beam passing space SPb3 facing the beam is low. As a result, the phenomenon of charge-up is less likely to occur as compared with the case where at least a part of the beam passing space SPb has the same degree of vacuum regardless of whether the sample W is an insulator or not. Further, since the scanning electron microscope SEMa does not have to collectively control the overall vacuum degree of the beam passing space SPb, compared with the case where the entire vacuum degree of the beam passing space SPb is controlled collectively. The vacuum degree of at least a part of the lowered beam passage space SPb can be returned to the original vacuum degree (that is, a relatively high vacuum degree) relatively quickly.

(1-4) Modification Example of Scanning Electron Microscope SEMa of the First Embodiment In the above description, when the sample W is an insulating material, the scanning electron microscope SEMa is a non-insulating material. The vacuum degree of at least a part of the beam passing space SPb is controlled so that the vacuum degree of at least a part of the beam passing space SPb is lower than that of the beam passing space SPb. However, the lower the degree of vacuum of at least a part of the beam passing space SPb, the higher the possibility that the electron beam EB passing through the beam passing space SPb is scattered by gas molecules. Therefore, the scanning electron microscope SEMa has a first operation of controlling the vacuum degree of at least a part of the beam passing space SPb so that the vacuum degree of at least a part of the beam passing space SPb is relatively low, and a beam passing. The second operation of controlling the vacuum degree of at least a part of the beam passing space SPb so that the vacuum degree of at least a part of the space SPb becomes relatively high may be repeated in a relatively short period of time. That is, the scanning electron microscope SEMa has the first operation of relatively lowering the degree of vacuum of at least a part of the beam passing space SPb to prioritize the prevention of charge-up rather than the prevention of scattering of the electron beam EB by gas molecules. The second operation of prioritizing the prevention of scattering of the electron beam EB by gas molecules rather than the prevention of charge-up by relatively increasing the degree of vacuum of at least a part of the beam passage space SPb is repeated in a relatively short period of time. You may. Specifically, for example, the scanning electron microscope SEMa repeats the first and second operations during a relatively short period in which the scanning electron microscope SEMa scans a part of the surface WSu of the sample W with the electron beam EB. You may. For example, the scanning electron microscope SEMa may repeat the first and second operations during a relatively short period in which the relative positions of the sample W and the beam irradiation device 1 do not change.

The scanning electron microscope SEMa may include a plurality of beam irradiation devices 1 having different degrees of vacuum in the beam passing space SPb. In this case, the scanning electron microscope SEMa determines one beam irradiation device 1 that irradiates the sample W with the electron beam EB among the plurality of beam irradiation devices 1 according to the characteristics (for example, electrical conductivity) of the sample W. Then, the sample W may be irradiated with the electron beam EB by using the one beam irradiation device 1. For example, when the electric conductivity of the sample W is high enough to behave as a non-insulating material, the scanning electron microscope SEMa has a relatively high degree of vacuum (or a degree of vacuum in the beam passing space SPb among the plurality of beam irradiation devices 1). The sample W may be irradiated with the electron beam EB by using one beam irradiation device 1 (higher or highest than a predetermined value). For example, when the electric conductivity of the sample W is low enough to behave as an insulator, the scanning electron microscope SEMa has a relatively low degree of vacuum (or a degree of vacuum in the beam passing space SPb among the plurality of beam irradiation devices 1). The electron beam EB may be irradiated to the sample W by using one beam irradiation device 1 (lower or lowest than a predetermined value).

As described above, considering that the distance D between the beam irradiation device 1 and the sample W changes when the degree of vacuum of the beam passing space SPb changes, the degree of vacuum and the distance D of the beam passing space SPb are still included. Is presumed to have a correlation. Therefore, the control device 4 may control the interval D based on the degree of vacuum of the beam passing space SPb in addition to or in place of the measurement results of the

position measuring devices

15 and 23. In this case, the scanning electron microscope SEMa may include a pressure gauge 16 as shown in FIG. The pressure gauge 16 may be capable of measuring at least one pressure in the beam passage spaces SPb1, SPb2 and SPb3. The pressure gauge 16 may be capable of measuring at least one pressure in the exhaust passages EP1 and EP2. The pressure gauge 16 may be capable of measuring the pressure in the pipe 127 connected to the beam passage space SPb.

In the above description, the opening 126 is connected to the gas supply device 6 via the pipe 127, the valve 1281, and the pipe 1291. However, the opening 126 may be connected to a low vacuum space having a vacuum degree lower than that of the beam passing space SPb via the pipe 127, the valve 1281, and the pipe 1291. The low vacuum space may be an atmospheric pressure space. When the scanning electron microscope SEMa is installed in an atmospheric pressure environment, the low vacuum space may be at least a part of the space in which the scanning electron microscope SEMa is installed. Even in this case, when the valve 1281 is opened, gas flows from the low vacuum space having a relatively low degree of vacuum toward at least a part of the beam passing space SPb having a relatively high degree of vacuum. Therefore, the same effect as the above-mentioned effect can be enjoyed. In this case, the scanning electron microscope SEMa does not have to be provided with the gas supply device 6.

In the above description, the opening 126 is connected to the exhaust device 7 via the pipe 127, the valve 1282, and the pipe 1292. However, the opening 126 may be connected to a high vacuum space having a higher degree of vacuum than the beam passing space SPb via the pipe 127, the valve 1282, and the pipe 1292. Even in this case, when the valve 1282 is opened, gas flows from at least a part of the beam passing space SPb having a relatively low degree of vacuum toward a high vacuum space having a relatively high degree of vacuum. That is, at least a part of the beam passing space SPb is exhausted. Therefore, the same effect as the above-mentioned effect can be enjoyed. In this case, the scanning electron microscope SEMa does not have to include the exhaust device 7.

In the above description, the scanning electron microscope SEMa provides both air supply of at least a part of the beam passing space SPb through the opening 126 and exhaust of at least a part of the beam passing space SPb through the opening 126. .. However, while the scanning electron microscope SEMa supplies at least a part of the beam passing space SPb through the opening 126, it does not have to exhaust at least a part of the beam passing space SPb through the opening 126. Good. In this case, the scanning electron microscope SEMa includes components (specifically, an exhaust device 7, a valve 1282 and a pipe 1292) used for exhausting at least a part of the beam passage space SPb through the opening 126. It does not have to be. Alternatively, the scanning electron microscope SEMa does not need to supply at least a part of the beam passing space SPb through the opening 126 while exhausting at least a part of the beam passing space SPb through the opening 126. Good. In this case, the scanning electron microscope SEMa is a component used for supplying air to at least a part of the beam passing space SPb through the opening 126 (specifically, the gas supply device 6, the valve 1281 and the pipe 1291). It is not necessary to have.

The gas supply device 6 supplies gas to at least a part of the beam passing space SPb through the opening 126, and in addition, by a peripheral region (for example, a vacuum region VSP) located at least a part around the vacuum region VSP. A space above the other part of the surface WSu of the uncovered sample W, for example, the space SP2) shown in FIG. 2 may be supplied with gas. Alternatively, the scanning electron microscope SEMa is provided in a peripheral region located at least a part around the vacuum region VSP in addition to the gas supply device 6 that supplies gas to at least a part of the beam passing space SPb through the opening 126. It may be provided with another gas supply device that supplies gas. In this case, the gas supplied by another gas supply device may be the same as or different from the gas supplied by the gas supply device 6.

The vacuum forming member 121 (or any member constituting the differential exhaust system 12) may be formed with a plurality of openings 126, each of which is connected to the gas supply device 6 and the exhaust device 7. In this case, the gas supply device 6 may supply gas to at least a part of the beam passage space SPb through each of the plurality of openings 126. The gas supply device 6 may supply gas to at least a part of the beam passage space SPb through at least one of the plurality of openings 126. The exhaust device 7 may exhaust at least a part of the beam passage space SPb through each of the plurality of openings 126. The exhaust device 7 may exhaust at least a part of the beam passage space SPb through at least one of the plurality of openings 126.

(2) Scanning electron microscope SEMb of the second embodiment
Subsequently, the scanning electron microscope SEM of the second embodiment (hereinafter, the scanning electron microscope SEM of the second embodiment will be referred to as “scanning electron microscope SEMb”) will be described. The scanning electron microscope SEMb of the second embodiment is different from the scanning electron microscope SEMa of the first embodiment described above in that it includes a beam irradiating device 1b instead of the beam irradiating device 1. .. Other features of the scanning electron microscope SEMb may be the same as those of the scanning electron microscope SEMa described above. Therefore, in the following, the structure of the beam irradiation device 1b will be described with reference to FIG. FIG. 11 is a cross-sectional view showing the structure of the beam irradiation device 1b included in the scanning electron microscope SEMb of the second embodiment. In the following description (including the description after the third embodiment), the same reference reference numerals will be given to the constituent requirements already described, and detailed description thereof will be omitted.

As shown in FIG. 11, the beam irradiation device 1b is different from the beam irradiation device 1 in that it includes a differential exhaust system 12b instead of the differential exhaust system 12. Further, the beam irradiation device 1b is different from the beam irradiation device 1 in that the beam optical system 11b is provided instead of the beam optical system 11. Other features of the beam irradiating device 1b may be the same as those of the beam irradiating device 1 described above.

The differential exhaust system 12b is different from the above-mentioned differential exhaust system 12 in that the opening 126 facing the beam passage space SPb2 does not have to be formed. Further, the differential exhaust system 12b is different from the above-mentioned differential exhaust system 12 in that it does not have to be provided with the pipe 127 connected to the opening 126 because the opening 126 is not formed. There is. Other features of the differential exhaust system 12b may be the same as those of the differential exhaust system 12 described above. However, also in the differential exhaust system 12b of the second embodiment, the opening 126 may be formed and the pipe 127 may be connected to the opening 126.

The beam optical system 11b is different from the beam optical system 11 described above in that an opening 126b is formed in the housing 111. Other features of the beam optical system 11b may be the same as those of the beam optical system 11 described above.

The opening 126b is formed so as to face the beam passing space SPb1. The opening 126b is formed so as to connect to the beam passage space SPb1. The opening 126b is formed above the beam ejection port 119 (that is, opposite to the sample W) that defines the lower boundary (that is, the end) of the beam passage space SPb1. The opening 126b is formed in a portion of the housing 111 facing the beam passing space SPb1. For example, the opening 126b is formed in the inner wall of the housing 111 that defines the beam passage space SPb1. FIG. 11 shows an example in which the aperture 126b is formed below the objective lens 115, but the formation position of the aperture 126b is not limited to this example.

A pipe 127b penetrating the housing 111 is connected to the opening 126b. Therefore, the pipe 127b is connected to the beam passage space SPb1 via the opening 126b. A gas supply device 6 is connected to the pipe 127b via a valve 1281 and a pipe 1291. Further, an exhaust device 7 is connected to the pipe 127b via a valve 1282 and a pipe 1292. Therefore, the gas supply device 6 includes a beam including a beam passing space SPb1 (further, beam passing spaces SPb2 and SPb3 connected to the beam passing space SPb1) via the pipe 1291, the valve 1281, the pipe 127b and the opening 126b. Gas can be supplied to at least a part of the passage space SPb. Further, the exhaust device 7 can exhaust at least a part of the beam passage space SPb through the pipe 1292, the valve 1282, the pipe 127b and the opening 126b. That is, the scanning electron microscope SEMb can control the degree of vacuum of at least a part of the beam passing SPb, similarly to the scanning electron microscope SEMa. Further, the scanning electron microscope SEMb can control the degree of vacuum of at least a part of the beam passing SPb and adjust the interval D in the same manner as the scanning electron microscope SEMb. The vacuum degree control and the interval D control itself performed in the second embodiment may be the same as the vacuum degree control and the interval D control performed in the first embodiment, and thus the detailed description thereof will be described. Is omitted.

As described above, the scanning electron microscope SEMb of the second embodiment has at least a part of the air supply of the beam passing space SPb and at least a part of the beam passing space SPb through the opening 126b facing the beam passing space SPb1. Exhausting. Even with such a scanning electron microscope SEMb, it is possible to enjoy the same effects as those that can be enjoyed by the scanning electron microscope SEMa described above.

In addition to at least one of the opening 126b facing the beam passing space SPb1 and the opening 126 facing the beam passing space SPb2, an opening facing the beam passing space SPb3 may be formed. The opening facing the beam passage space SPb3 may be formed in, for example, the differential exhaust system 12b. As an example, the opening facing the beam passage space SPb3 may be formed on the injection surface 12LS of the differential exhaust system 12b. Such an opening facing the beam passage space SPb3 may face the surface WSu of the sample W. Even in this case, the gas supply device 6 includes the beam passing space SPb3 (further, the beam passing spaces SPb1 and SPb2 connected to the beam passing space SPb3) through the opening facing the beam passing space SPb3. Gas can be supplied to at least a part of the beam passing space SPb. Further, the exhaust device 7 can exhaust at least a part of the beam passing space SPb through the opening facing the beam passing space SPb3.

A modified example of the scanning electron microscope SEMa of the first embodiment can also be applied to the scanning electron microscope SEMb of the second embodiment. That is, in the description of the modification of the scanning electron microscope SEMa of the first embodiment, the words "opening 126", "pipe 127" and "scanning electron microscope SEMa" are referred to as "opening 126b (or beam passing space SPb3), respectively. The scanning type of the second embodiment is replaced with the words "opening facing the opening)", "pipe 127b (or the pipe connected to the opening facing the beam passage space SPb3)" and "scanning electron microscope SEMb". This will explain a modified example in which the electron microscope SEMb can be adopted.

(3) Scanning electron microscope SEMc of the third embodiment
Subsequently, the scanning electron microscope SEM of the third embodiment (hereinafter, the scanning electron microscope SEM of the third embodiment will be referred to as “scanning electron microscope SEMc”) will be described. The scanning electron microscope SEMc of the third embodiment is different from the scanning electron microscope SEMb of the second embodiment described above in that it includes a beam irradiating device 1c instead of the beam irradiating device 1b. .. Other features of the scanning electron microscope SEMc may be the same as those of the scanning electron microscope SEMb described above. Therefore, in the following, the structure of the beam irradiation device 1c will be described with reference to FIG. FIG. 12 is a cross-sectional view showing the structure of the beam irradiation device 1c included in the scanning electron microscope SEMc of the third embodiment.

As shown in FIG. 12, the beam irradiation device 1c is the same as the beam irradiation device 1b in that it includes a beam optical system 11b and a differential exhaust system 12b. The beam irradiator 1c is different from the beam irradiator 1b in that it further includes a pipe 127c. Other features of the beam irradiating device 1c may be the same as those of the beam irradiating device 1b described above.

The pipe 127c extends from the opening 126b toward the beam passage space SPb2 via the beam passage space SPb1. One end of the pipe 127c is connected to the opening 126b. The other end of the pipe 127c is arranged in the beam passage space SPb2. The other end of pipe 127c may face downward. The other end of the pipe 127c may face the surface WSu of the sample W via the beam passage spaces SPb2 and SPb3. The pipe 127c may be integrated with the pipe 127b. In this case, the gas supply device 6 is connected to the beam passage space SPb2 (further, the beam passage spaces SPb1 and SPb3 connected to the beam passage space SPb2) via the pipe 1291, the valve 1281, the pipe 127b, the opening 126b, and the pipe 127c. A gas can be supplied to at least a part of the beam passage space SPb including the above. Further, the exhaust device 7 can exhaust at least a part of the beam passage space SPb through the pipe 1292, the valve 1282, the pipe 127b, the opening 126b, and the pipe 127c. That is, the scanning electron microscope SEMc can control the degree of vacuum of at least a part of the beam passing SPb and adjust the interval D in the same manner as the scanning electron microscope SEMa. Since the control of the degree of vacuum and the control of the interval D performed in the third embodiment may be the same as the control of the degree of vacuum and the control of the interval D performed in the first embodiment, a detailed description thereof will be given. Is omitted.

As described above, the scanning electron microscope SEMc of the third embodiment supplies air to at least a part of the beam passing space SPb via the pipe 127c extending from the opening 126b facing the beam passing space SPb1 to the beam passing space SPb2. At least a part of the beam passing space SPb is exhausted. Even with such a scanning electron microscope SEMc, it is possible to enjoy the same effects as those that can be enjoyed by the scanning electron microscope SEMb described above.

Note that the pipe 127c may extend from the opening 126b toward the beam passage space SPb1. That is, the other end of the pipe 127c may be arranged in the beam passage space SPb1. The other end of the pipe 127c may face upward. The pipe 127c may extend from the opening 126b toward the beam passing space SPb3 via the beam passing spaces SPb1 and SPb2. That is, the other end of the pipe 127c may be arranged in the beam passage space SPb3. Also in the scanning electron microscope SEMa of the first embodiment, the pipe extending from the opening 126 facing the beam passing space SPb2 to the beam passing space SPb1 via the beam passing space SPb2 and the opening 126 via the beam passing space SPb2. It may be provided with at least one of the pipes extending toward the beam passage space SPb3.

(4) Scanning electron microscope SEMd of the fourth embodiment
Subsequently, the scanning electron microscope SEM of the fourth embodiment (hereinafter, the scanning electron microscope SEM of the fourth embodiment will be referred to as “scanning electron microscope SEMd”) will be described. The scanning electron microscope SEMd of the fourth embodiment is different from the scanning electron microscope SEMa of the first embodiment described above in that it includes a beam irradiating device 1d instead of the beam irradiating device 1. .. Other features of the scanning electron microscope SEMd may be the same as those of the scanning electron microscope SEMa described above. Therefore, in the following, the structure of the beam irradiation device 1d will be described with reference to FIGS. 13 and 14. 13 and 14 are cross-sectional views showing the structure of the beam irradiation device 1d included in the scanning electron microscope SEMd of the fourth embodiment.

As shown in FIGS. 13 and 14, the beam irradiation device 1d is different from the beam irradiation device 1 in that the aperture member 16d is provided. Other features of the beam irradiating device 1d may be the same as those of the beam irradiating device 1 described above.

The aperture member 16d is arranged between the beam passing space SPb1 and the beam passing space SPb2. That is, the aperture member 16d is arranged (at or near the boundary between the beam passing space SPb1 and the beam passing space SPb2). For example, a beam ejection port 119 of the beam optical system 11 and an opening 120 of the differential exhaust system 12 are formed at the boundary between the beam passing space SPb1 and the beam passing space SPb2. Therefore, the aperture member 16d may be arranged at the beam ejection port 119 or the opening 120. The aperture member 16d may be arranged in the vicinity of the beam ejection port 1231 or the opening 120.

The aperture member 16d is a plate-shaped member having a circular (or other arbitrary shape) opening 161d. The opening 161d is an opening through which the electron beam EB can pass. Therefore, the electron beam EB ejected by the electron gun 113 propagates from the beam passing space SPb1 to the beam passing space SPb2 through the opening 161d. Therefore, the irradiation of the electron beam EB on the sample W is not blocked by the aperture member 16d. Since the electron beam EB passes through the opening 161d, the opening 161d may be formed on the optical axis AX of the beam optical system 11 or in the vicinity of the optical axis AX. The aperture member 16d may be arranged so that the aperture 161d is located on the optical axis AX of the beam optical system 11 or in the vicinity of the optical axis AX.

The aperture member 16d is arranged inside the electromagnetic lens 114 and / or the objective lens 115. That is, the aperture member 16d is arranged closer to the optical axis AX of the beam optical system 11 (that is, the optical axis AX of the electromagnetic lens 114 and / or the objective lens 115) than the electromagnetic lens 114 and / or the objective lens 115. Therefore, the aperture 161d formed in the aperture member 16d is also formed inside the electromagnetic lens 114 and / or the objective lens 115. However, the aperture member 16d may be arranged at a position different from the inside of the electromagnetic lens 114 and / or the objective lens 115. The opening 161d may be formed at a position different from the inside of the electromagnetic lens 114 and / or the objective lens 115.

The aperture member 16d is arranged above the electron detector 117. That is, the aperture member 16d is arranged so that the electron detector 117 is arranged between the aperture member 16d and the sample W. Therefore, the opening 161d formed in the aperture member 16d is also formed above the electron detector 117. The opening 161d is also formed so that the electron detector 117 is arranged between the opening 161d and the sample W. However, the aperture member 16d may be arranged at another position. The opening 161d may be arranged at other positions.

The outer edge of the aperture member 16d is at least the housing 111 (for example, the inner wall of the housing 111 that defines the beam passage space SPb1) and the vacuum forming member 121 (for example, the inner wall of the vacuum forming member 121 that defines the beam passage space SPb2). It may be in contact with one side. In this case, the inflow of gas from the beam passing space SPb1 into the beam passing space SPb2 and the inflow of gas from the beam passing space SPb2 into the beam passing space SPb1 are performed through the opening 161d. However, at least a part of the outer edge of the aperture member 16d may not be in contact with at least one of the housing 111 and the vacuum forming member 121 (that is, there may be a gap). In this case, the inflow of gas from the beam passing space SPb1 into the beam passing space SPb2 and the inflow of gas from the beam passing space SPb2 into the beam passing space SPb1 are the aperture member 16d, the housing 111, and the vacuum in addition to the opening 161d. This is done through a gap between the forming member 121 and at least one of them. In any case, when the aperture member 16d is arranged, the inflow of gas from the beam passing space SPb1 into the beam passing space SPb2 and the inflow of gas from the beam passing space SPb2 into the beam passing space SPb1 It is partially blocked by the aperture member 16d.

Therefore, in a situation where the gas supply device 6 supplies gas to at least a part of the beam passing space SPb2 to reduce the degree of vacuum of at least a part of the beam passing space SPb2, at least a part of the beam passing space SPb1. The degree of vacuum does not decrease as much as the degree of vacuum in the beam passing space SPb2. Further, in a situation where the exhaust device 7 exhausts at least a part of the beam passing space SPb2 to increase the vacuum degree of at least a part of the beam passing space SPb2, the vacuum degree of at least a part of the beam passing space SPb1 becomes a beam. It does not increase as much as the degree of vacuum of the passage space SPb2. Therefore, when the aperture member 16d is arranged, the air supply and exhaust device to at least a part of the beam passing space SPb2 using the gas supply device 6 is compared with the case where the aperture member 16d is not arranged. The influence of at least a part of the exhaust gas of the beam passing space SPb2 using 7 on the degree of vacuum of the beam passing space SPb1 becomes even smaller. That is, the scanning electron microscope SEMd locally (in other words, selectively) the vacuum degree of at least a part of the beam passing space SPb2 while further reducing the influence on the vacuum degree of the beam passing space SPb1. ) It becomes easier to control. The scanning electron microscope SEMd can locally (in other words, selectively) control the vacuum degree of at least a part of the beam passing space SPb2 without significantly changing the vacuum degree of the beam passing space SPb1.

The opening 161d of the aperture member 16d may be an opening having a variable size (for example, diameter). That is, the area of the opening 161d may be variable. 13 is a cross-sectional view showing an opening 161d having a relatively large area, and FIG. 14 is a cross-sectional view showing an opening 161d having a relatively small area. In this case, the scanning electron microscope SEMd controls the degree of vacuum of at least a part of the beam passing space SPb by using at least one of the gas supply device 6 and the exhaust device 7 under the control of the control device 4, and the opening 161d. The area of may be adjusted. In particular, the scanning electron microscope SEMd has an opening 161d when the degree of vacuum of at least a part of the beam passing space SPb is changed by using at least one of the gas supply device 6 and the exhaust device 7 under the control of the control device 4. You may change it according to the area of.

For example, when the gas supply device 6 supplies gas to at least a part of the beam vacuum space SPb2, the degree of vacuum of at least a part of the beam vacuum space SPb2 decreases. At this time, when the area of the opening 161d is adjusted so that the area of the opening 161d decreases (that is, the opening 161d becomes smaller), the beam passing space connected to the beam vacuum space SPb2 with the aperture member 16d sandwiched between them. The amount of decrease in the degree of vacuum of SPb1 is smaller than the amount of decrease in the degree of vacuum of at least a part of the beam vacuum space SPb2. Further, when the exhaust device 7 exhausts at least a part of the beam vacuum space SPb2, the degree of vacuum of at least a part of the beam vacuum space SPb2 increases. At this time, when the area of the opening 161d is adjusted so that the area of the opening 161d decreases (that is, the opening 161d becomes smaller), the beam passing space connected to the beam vacuum space SPb2 with the aperture member 16d sandwiched between them. The amount of increase in the degree of vacuum of SPb1 is likely to be smaller than the amount of increase in the degree of vacuum of at least a part of the beam vacuum space SPb2. The difference in the degree of vacuum between the beam passing space SPb1 and the beam passing space SPb2 (furthermore, the beam passing space SPb3) thus generated is maintained by the exhaust resistance of the opening 161d.

Therefore, the scanning electron microscope SEMd reduces the area of the opening 161d when controlling the vacuum degree of at least a part of the beam passing space SPb, thereby reducing the vacuum degree of the beam passing space SPb1 and the vacuum of the beam passing space SPb2. The difference from the degree can be increased. Conversely, the scanning electron microscope SEMd increases the difference between the vacuum degree of the beam passage space SPb1 and the vacuum degree of the beam passage space SPb2 when controlling the vacuum degree of at least a part of the beam passage space SPb. If desired, the area of the opening 161d may be reduced as compared with the case where the difference between the degree of vacuum of the beam passing space SPb1 and the degree of vacuum of the beam passing space SPb2 is not desired to be increased.

As an example of a situation in which the difference between the degree of vacuum of the beam passing space SPb1 and the degree of vacuum of the beam passing space SPb2 is desired to be increased, the degree of vacuum of the beam passing space SPb1 is maintained relatively high and the beam passing space SPb2 is maintained. There is a situation where you want to reduce the degree of vacuum. That is, as an example of a situation in which the difference between the degree of vacuum of the beam passing space SPb1 and the degree of vacuum of the beam passing space SPb2 is desired to be increased, the degree of vacuum of the beam passing space SPb1 is maintained relatively high and the beam passing space SPb2 is maintained. There is a situation where the degree of vacuum of is smaller than the degree of vacuum of the beam passing space SPb1. In this case, since the degree of vacuum of the beam passing space SPb1 is maintained relatively high, the degree of vacuum of the beam passing space SPb1 is increased when the reduced degree of vacuum of the beam passing space SPb2 is returned (that is, increased). It does not have to be increased so much. Therefore, the degree of vacuum of the beam passing space SPb including the beam passing space SPb2 can be restored relatively quickly. Further, since the degree of vacuum of the beam passing space SPb1 is maintained relatively high, the devices (for example, electron gun 113, electromagnetic lens 114, objective lens 115, deflection) included in the beam optical system 12 facing the beam passing space SPb1 are provided. The device 116 and the electron detector 117) are properly protected from gas molecules.

Alternatively, when the area of the opening 161d is adjusted so that the area of the opening 161d increases (that is, the opening 161d becomes larger), the beam passing space SPb1 becomes the beam passing space SPb2 or the beam passing space SPb2 becomes the beam passing space. Gas easily flows into SPb1. Therefore, the scanning electron microscope SEMd can reduce the difference between the degree of vacuum of the beam passing space SPb1 and the degree of vacuum of the beam passing space SPb2 by increasing the area of the opening 161d. Conversely, when the scanning electron microscope SEMd wants to reduce the difference between the degree of vacuum of the beam passing space SPb1 and the degree of vacuum of the beam passing space SPb2, the degree of vacuum of the beam passing space SPb1 and the degree of vacuum of the beam passing space SPb2 The area of the opening 161d may be increased as compared with the case where the difference from the degree of vacuum of is not desired to be reduced.

As an example of a situation in which the difference between the vacuum degree of the beam passing space SPb1 and the vacuum degree of the beam passing space SPb2 is desired to be reduced, the vacuum of the beam passing space SPb2 is maintained while the vacuum degree of the beam passing space SPb1 is relatively high. After reducing the degree, there is a situation in which the degree of vacuum of the beam passing space SPb2 is desired to be restored (that is, increased). In this case, as described above, when the reduced vacuum degree of the beam passing space SPb2 is returned (that is, increased), the vacuum degree of the beam passing space SPb1 does not have to be increased so much, so that the beam passing space SPb2 is changed. The degree of vacuum of the included beam passage space SPb can be restored relatively quickly.

As described above, the scanning electron microscope SEMd of the fourth embodiment enjoys the same effect as the effect that can be enjoyed by the scanning electron microscope SEMa described above, but is independent of the degree of vacuum of the beam passing space SPb1. It becomes easy to locally (in other words, selectively) control the degree of vacuum of at least a part of the beam passing space SPb2.

The aperture member 16d includes a first space in the beam passing space SPb where the gas supply device 6 and / or an exhaust device 7 is desired to positively control the degree of vacuum, and the gas supply device 6 and / or the gas supply device 6 in the beam passing space SPb. / Or it is arranged between the second space and the exhaust device 7 which does not want to positively control the degree of vacuum (or does not want to influence the operation of controlling the degree of vacuum in the first space). May be good. In this case, the scanning electron microscope SEMd can easily control the vacuum degree of the second space locally (in other words, selectively) independently of the vacuum degree of the second space. The first space may include a space facing the opening 126. Alternatively, the scanning electron microscope SEMb of the second embodiment may include the aperture member 16d, and in this case, the first space may include a space facing the opening 126b. Alternatively, the scanning electron microscope SEMc of the third embodiment may include the aperture member 16d, in which case the first space does not include a space facing the other end of the pipe 127c. May be good. On the other hand, the second space may include a space located on the side farther from the sample W than the first space.

As shown in FIG. 15, the aperture member 16d may be arranged so that the opening 161d is located at the deflection fulcrum (for example, the upper deflection fulcrum) P of the deflector 116. That is, as shown in FIG. 15, the opening 161d may be formed so as to be located at the deflection fulcrum P of the deflector 116. In this case, the possibility that the electron beam EB deflected by the deflector 116 cannot pass through the opening 161d is reduced. That is, the possibility that the electron beam EB is eclipsed by the aperture member 16d is reduced. Alternatively, the aperture member 16d may be located above the deflector 116. The opening 161d may be formed above the deflector 116. That is, the aperture member 16d may be arranged so that the deflector 116 is located between the aperture member 16d and the sample W. The opening 161d may be formed so that the deflector 116 is located between the opening 161d and the sample W. Even in this case, the possibility that the electron beam EB is eclipsed by the aperture member 16d is reduced.

As shown in FIG. 16A, the aperture member 16d may be arranged between the upper end and the lower end of the electromagnetic lens 114 with respect to the direction along the optical axis AX of the electromagnetic lens 114. The aperture member 16d may be arranged inside the electromagnetic lens 114. At this time, in particular, as shown in FIG. 16A, the opening 161d is located at a position near the optical axis AX of the electromagnetic lens 114 or the optical axis AX, and is in a direction along the optical axis AX of the electromagnetic lens 114. It may be arranged between the upper end and the lower end of the electromagnetic lens 114. Alternatively, as shown in FIG. 16A, the aperture member 16d may be arranged between the upper end and the lower end of the objective lens 115 with respect to the direction along the optical axis AX of the objective lens 115. The aperture member 16d may be arranged inside the objective lens 115. At this time, in particular, as shown in FIG. 16A, the opening 161d is located at a position near the optical axis AX of the objective lens 115 or the optical axis AX, and is in a direction along the optical axis AX of the objective lens 115. It may be arranged between the upper end and the lower end of the objective lens 115. In this case, the possibility that the electron beam EB controlled by the electromagnetic lens 114 and / or the objective lens 115 cannot pass through the aperture 161d is reduced. That is, the possibility that the electron beam EB is eclipsed by the aperture member 16d is reduced.

The aperture member 16d is located near the optical axis AX of the objective lens 115 or the optical axis AX, and is located between the upper end and the lower end of the objective lens 115 with respect to the direction along the optical axis AX of the objective lens 115. When the opening 161d of the above is formed, as shown in FIG. 16B, the deflector 116 is arranged so that the deflection fulcrum (for example, the lower deflection fulcrum) P of the deflector 116 is located at the opening 161d. / May be adjusted.

(5) Scanning electron microscope SEMe of the fifth embodiment
Subsequently, the scanning electron microscope SEM of the fifth embodiment (hereinafter, the scanning electron microscope SEM of the fifth embodiment will be referred to as “scanning electron microscope SEMe”) will be described. The scanning electron microscope SEMe of the fifth embodiment is different from the scanning electron microscope SEMa of the first embodiment described above in that it includes a beam irradiation device 1e instead of the beam irradiation device 1. .. Other features of the scanning electron microscope SEMe may be the same as those of the scanning electron microscope SEMa described above. Therefore, in the following, the structure of the beam irradiation device 1e will be described with reference to FIG. FIG. 17 is a cross-sectional view showing the structure of the beam irradiation device 1e included in the scanning electron microscope SEMe of the fifth embodiment.

As shown in FIG. 17, the beam irradiation device 1e is different from the beam irradiation device 1 in that it includes a differential exhaust system 12e instead of the differential exhaust system 12. Other features of the beam irradiating device 1e may be the same as those of the beam irradiating device 1 described above. In the differential exhaust system 12e, a plurality of openings 126e (in the example shown in FIG. 17, two openings 126e-1 and 126e-2) are formed in the vacuum forming member 121 as compared with the above-mentioned differential exhaust system 12. It is different in that it is. The characteristics of the opening 126e may be the same as the characteristics of the opening 126. Other features of the differential exhaust system 12e may be the same as those of the differential exhaust system 12 described above.

A pipe 127e-1 penetrating the vacuum forming member 121 is connected to the opening 126e-1. A gas supply device 6 is connected to the pipe 127e-1 via a valve 1281 and a pipe 1291. Therefore, the gas supply device 6 can supply gas to at least a part of the beam passage space SPb via the pipe 1291, the valve 1281, the pipe 127e-1, and the opening 126e-1.

On the other hand, a pipe 127e-2 penetrating the vacuum forming member 121 is connected to the opening 126e-2. An exhaust device 7 is connected to the pipe 127e-2 via a valve 1282 and a pipe 1292. Therefore, the exhaust device 7 can exhaust at least a part of the beam passage space SPb through the pipe 1292, the valve 1282, the pipe 127e-2, and the opening 126e-2.

As described above, the scanning electron microscope SEMe of the fifth embodiment supplies air at least a part of the beam passing space SPb and exhausts at least a part of the beam passing space SPb through different openings 126e, respectively. .. Even with such a scanning electron microscope SEMe, the same effects as those that can be enjoyed by the scanning electron microscope SEMa described above can be enjoyed.

A modified example of the scanning electron microscope SEMa of the first embodiment can also be applied to the scanning electron microscope SEMe of the fifth embodiment. That is, in the description of the modification of the scanning electron microscope SEMa of the first embodiment, the words "opening 126", "pipe 127" and "scanning electron microscope SEMa" are referred to as "opening 126e-1 (or opening 126e", respectively. -2) ”,“ Pipe 127e-1 (or Pipe 127e-2) ”and“ Scanning electron microscope SEMe ”, a modification in which the scanning electron microscope SEMe of the fifth embodiment can be adopted. It becomes an explanation of.

Further, at least a part of the constituent requirements of the scanning electron microscope SEMb of the second embodiment may be combined with the scanning electron microscope SEMe of the fifth embodiment. For example, in the scanning electron microscope SEMe, at least one of the plurality of openings 126b may face the beam passing space SPb1 (or the beam passing space SPb3). Further, at least a part of the constituent requirements of the scanning electron microscope SEMc of the third embodiment may be combined with the scanning electron microscope SEMe of the fifth embodiment. For example, in the scanning electron microscope SEMe, a pipe extending toward the beam passing space SPb1 (or the beam passing space SPb2 or SPb3) may be connected to at least one of the plurality of openings 126e. Further, at least a part of the constituent requirements of the scanning electron microscope SEMd of the fourth embodiment may be combined with the scanning electron microscope SEMe of the fifth embodiment. For example, the scanning electron microscope SEMe may include an aperture member 16d.

(6) Scanning electron microscope SEMf of the sixth embodiment
Subsequently, with reference to FIGS. 18 and 19, the scanning electron microscope SEM of the sixth embodiment (hereinafter, the scanning electron microscope SEM of the sixth embodiment will be referred to as “scanning electron microscope SEMf”) will be described. To do. FIG. 18 is a cross-sectional view showing the structure of the scanning electron microscope SEMf of the sixth embodiment. FIG. 19 is a cross-sectional view showing the structure of the beam irradiation device 1f included in the scanning electron microscope SEMf of the sixth embodiment.

As shown in FIG. 18, the scanning electron microscope SEMf of the sixth embodiment has a gas supply device 6, an exhaust device 7,

valves

1281 and 1282, as compared with the scanning electron microscope SEMa of the first embodiment described above. It also differs in that it does not have to be provided with

pipes

1291 and 1292. Further, the scanning electron microscope SEMf is different from the scanning electron microscope SEMa in that the beam irradiation device 1f is provided instead of the beam irradiation device 1. Other features of the scanning electron microscope SEMf may be the same as those of the scanning electron microscope SEMa described above.

As shown in FIG. 19, the beam irradiation device 1f is different from the beam irradiation device 1 in that it includes a differential exhaust system 12f instead of the differential exhaust system 12. Other features of the beam irradiating device 1f may be the same as those of the beam irradiating device 1 described above. The differential exhaust system 12f is different from the above-mentioned differential exhaust system 12 in that the opening 126 facing the beam passage space SPb2 does not have to be formed. Further, the differential exhaust system 12b is different from the above-mentioned differential exhaust system 12 in that it does not have to be provided with the pipe 127 connected to the opening 126 because the opening 126 is not formed. There is. Other features of the differential exhaust system 12f may be the same as those of the differential exhaust system 12 described above.

Since the scanning electron microscope SEMf of the sixth embodiment does not include the gas supply device 6 and the exhaust device 7, the gas supply device 6 and the exhaust device 7 are used to control the degree of vacuum of the beam passing space SPb. Can not do it. The scanning electron microscope SEMf uses at least the beam passage space SPb by controlling the distance D between the beam irradiation device 1 and the sample W in addition to or in place of using the gas supply device 6 and the exhaust device 7. Control some degree of vacuum. That is, the scanning electron microscope SEMf controls the degree of vacuum of at least a part of the beam passing space SPb without using the gas supply device 6 and the exhaust device 7, and the distance D between the beam irradiation device 1 and the sample W. To control.

Specifically, the smaller the interval D, the smaller the volume of the space between the beam irradiation device 1 and the sample W. The smaller the volume of the space between the beam irradiation device 1 and the sample W, the area where the vacuum region VSP formed between the beam irradiation device 1 and the sample W faces the peripheral region located around the vacuum region VSP. Becomes smaller. The smaller the area of the vacuum region VSP facing the peripheral region, the smaller the amount of gas flowing from the peripheral region into the vacuum region VSP. The smaller the amount of gas flowing from the peripheral region into the vacuum region VSP, the higher the degree of vacuum in the vacuum region VSP. The higher the degree of vacuum of the vacuum region VSP, the higher the degree of vacuum of at least a part of the beam passing space SPb3 included in the vacuum region VSP. Therefore, the scanning electron microscope SEMf can increase the degree of vacuum of at least a part of the beam passing space SPb3 by controlling the interval D so that the interval D decreases under the control of the control device 4. .. That is, the scanning electron microscope SEMf increases the degree of vacuum of at least a part of the beam passing space SPb3 by bringing the beam irradiation device 1 (particularly, the vacuum forming member 121) closer to the sample W under the control of the control device 4. Can be made to. Further, since the beam passing space SPb3 is connected to the beam passing spaces SPb1 and SPb2, the scanning electron microscope SEMf samples the beam irradiating device 1 (particularly, the vacuum forming member 121) under the control of the control device 4. By approaching W, the degree of vacuum of at least a part of the beam passing space SPb including the beam passing spaces SPb1 to SPb3 can be increased.

For example, when the distance adjusting system 14 adjusts the distance D by applying a force acting to separate the beam irradiation device 1 and the sample W in the Z-axis direction to the flange member 13 (see FIG. 6). When the force applied to the flange member 13 from the interval adjusting system 14 is reduced, the beam irradiation device 1 approaches the sample W. Therefore, the control device 4 increases the degree of vacuum of at least a part of the beam passing space SPb by controlling the interval adjusting system 14 so that the force applied to the flange member 13 from the interval adjusting system 14 is reduced. be able to. For example, when the stage drive system 23 adjusts the interval D by applying a force acting to separate the beam irradiation device 1 and the sample W in the Z-axis direction to the stage 22 (see FIG. 6). When the force applied to the stage 22 from the stage drive system 23 decreases, the beam irradiation device 1 approaches the sample W. Therefore, the control device 4 controls the stage drive system 23 so that the force applied to the stage 22 from the stage drive system 23 is reduced, thereby increasing the degree of vacuum of at least a part of the beam passing space SPb. Can be done. For example, when the distance adjusting system 14 adjusts the distance D by applying a force acting to bring the beam irradiation device 1 and the sample W closer to each other in the Z-axis direction to the flange member 13 (see FIG. 7). If the force applied to the flange member 13 from the interval adjusting system 14 increases, the beam irradiation device 1 approaches the sample W. Therefore, the control device 4 increases the degree of vacuum of at least a part of the beam passing space SPb by controlling the interval adjusting system 14 so that the force applied to the flange member 13 from the interval adjusting system 14 increases. be able to. For example, when the stage drive system 23 adjusts the interval D by applying a force acting to bring the beam irradiation device 1 and the sample W closer to each other in the Z-axis direction to the stage 22 (see FIG. 7). When the force applied to the stage 22 from the stage drive system 23 increases, the beam irradiation device 1 approaches the sample W. Therefore, the control device 4 increases the degree of vacuum of at least a part of the beam passing space SPb by controlling the stage drive system 23 so that the force applied to the stage 22 from the stage drive system 23 increases. Can be done.

On the other hand, the larger the interval D, the larger the volume of the space between the beam irradiation device 1 and the sample W. As the volume of the space between the beam irradiation device 1 and the sample W increases, the vacuum region VSP formed between the beam irradiation device 1 and the sample W faces the peripheral region located around the vacuum region VSP. The area becomes large. The larger the area of the vacuum region VSP facing the peripheral region, the larger the amount of gas flowing from the peripheral region into the vacuum region VSP. As the amount of gas flowing from the peripheral region into the vacuum region VSP increases, the degree of vacuum in the vacuum region VSP decreases. The lower the degree of vacuum of the vacuum region VSP, the lower the degree of vacuum of at least a part of the beam passing space SPb3 included in the vacuum region VSP. Therefore, the scanning electron microscope SEMf can reduce the degree of vacuum of at least a part of the beam passing space SPb3 by controlling the interval D so that the interval D increases under the control of the control device 4. .. That is, in the scanning electron microscope SEMf, the beam irradiation device 1 (particularly, the vacuum forming member 121) is separated from the sample W under the control of the control device 4, so that at least one of the beam passage spaces SPb including the beam passage space SPb3 The degree of vacuum of the part can be reduced.

For example, when the distance adjusting system 14 adjusts the distance D by applying a force acting to separate the beam irradiation device 1 and the sample W in the Z-axis direction to the flange member 13 (see FIG. 6). When the force applied to the flange member 13 from the interval adjusting system 14 increases, the beam irradiation device 1 moves away from the sample W. Therefore, the control device 4 reduces the degree of vacuum of at least a part of the beam passing space SPb by controlling the interval adjusting system 14 so that the force applied to the flange member 13 from the interval adjusting system 14 increases. be able to. For example, when the stage drive system 23 adjusts the interval D by applying a force acting to separate the beam irradiation device 1 and the sample W in the Z-axis direction to the stage 22 (see FIG. 6). When the force applied to the stage 22 from the stage drive system 23 increases, the beam irradiation device 1 moves away from the sample W. Therefore, the control device 4 reduces the degree of vacuum of at least a part of the beam passing space SPb by controlling the stage drive system 23 so that the force applied to the stage 22 from the stage drive system 23 increases. Can be done. For example, when the spacing adjusting system 14 adjusts the spacing D by applying a force acting to bring the beam irradiation device 1 and the sample W closer to each other in the Z-axis direction to the flange member 13 (see FIG. 7). When the force applied to the flange member 13 from the interval adjusting system 14 is reduced, the beam irradiation device 1 is separated from the sample W. Therefore, the control device 4 reduces the degree of vacuum of at least a part of the beam passing space SPb by controlling the interval adjusting system 14 so that the force applied to the flange member 13 from the interval adjusting system 14 is reduced. be able to. For example, when the stage drive system 23 adjusts the interval D by applying a force acting to bring the beam irradiation device 1 and the sample W closer to each other in the Z-axis direction to the stage 22 (see FIG. 7). When the force applied to the stage 22 from the stage drive system 23 decreases, the beam irradiation device 1 moves away from the sample W. Therefore, the control device 4 reduces the degree of vacuum of at least a part of the beam passing space SPb by controlling the stage drive system 23 so that the force applied to the stage 22 from the stage drive system 23 is reduced. Can be done.

As described above, the scanning electron microscope SEMf of the sixth embodiment can control the degree of vacuum of at least a part of the beam passing space SPb without using the gas supply device 6 and the exhaust device 7. As a result, the scanning electron microscope SEMf controls (for example, changes) the distance D between the beam irradiation device 1 and the sample W, so that the operation mode of the scanning electron microscope SEMa can be changed to the vacuum region VSS described above. Can be switched between a first mode in which is used in the first pressure range and a second mode in which the vacuum region VSP is used in the second pressure range.

As an example, in the scanning electron microscope SEMa, when the sample W is an insulating material, the interval D is larger than when the sample W is a non-insulating material (as a result, at least the beam passing space SPb is large. The interval D may be controlled so that a part of the degree of vacuum becomes low). As a result, even when the gas supply device 6 and the exhaust device 7 are not used, the phenomenon of charge-up is less likely to occur.

At least one of the above-mentioned SEMa of the first embodiment to the scanning electron microscope SEMe of the fifth embodiment including the gas supply device 6 and the exhaust device 7, the

valves

1281 and 1282, and the

pipes

1291 and 1292 is also a beam. By controlling (for example, changing) the distance D between the irradiation device 1 and the sample W, the degree of vacuum of at least a part of the beam passing space SPb may be controlled.

It should be noted that at least a part of the constituent requirements of the scanning electron microscope SEMd of the fourth embodiment may be combined with the scanning electron microscope SEMf of the sixth embodiment. For example, the scanning electron microscope SEMf may include an aperture member 16d.

(7) Scanning electron microscope SEMg of the seventh embodiment
Subsequently, with reference to FIG. 20, the scanning electron microscope SEM of the seventh embodiment (hereinafter, the scanning electron microscope SEM of the seventh embodiment will be referred to as “scanning electron microscope SEMg”) will be described. FIG. 20 is a cross-sectional view showing the structure of the scanning electron microscope SEMg of the seventh embodiment.

As shown in FIG. 20, the scanning electron microscope SEMg of the seventh embodiment has a gas supply device 6, an exhaust device 7,

valves

pipes

1291 and 1292. Further, in the scanning electron microscope SEMg, as compared with the scanning electron microscope SEMa, instead of the beam irradiating device 1, the beam irradiating device 1f (that is, even if the opening 126 described in the sixth embodiment is not formed). It differs in that it includes a beam irradiator 1f) with a good differential exhaust system 12f. Further, the scanning electron microscope SEMg is different from the scanning electron microscope SEMa in that it includes a position adjusting system 14 g instead of the interval adjusting system 14. Further, the scanning electron microscope SEMg is different from the scanning electron microscope SEMa in that it further includes 8 g of a measuring device. Other features of the scanning electron microscope SEMg may be the same as those of the scanning electron microscope SEMa described above.

The position adjustment system 14g moves the beam irradiation device 1f along at least one of the θX direction and the θY direction as compared with the above-mentioned interval adjustment system 14 (furthermore, the beam along the θZ direction if necessary). By moving the irradiation device 1f), the posture of the beam irradiation device 1f with respect to the sample W (specifically, the amount of inclination, which is substantially the tilt angle) can be adjusted. For example, the position adjusting system 14g aligns the beam irradiating device 1f along at least one of the θX direction, the θY direction, and the θZ direction so that the injection surface 12LS of the beam irradiating device 1f is parallel to the surface WSu of the sample W. You may move it. However, when it is not necessary to electrically adjust the relative posture of the beam irradiation device 1f with respect to the sample W, instead of the position adjusting system 14g, a position adjusting member such as a shim is used as a support member 32 and a flange member. It may be arranged between 13 and 13. In this case, if the size and / or number of shims is changed, the relative posture of the beam irradiator 1f with respect to the sample W is adjusted. Other features of the position adjusting system 14g may be the same as those of the spacing adjusting system 14.

The measuring device 8g measures (in other words, detects) the position of the object to be measured. The measuring device 8g measures the position of the object to be measured in the three-dimensional coordinate space (specifically, the measurement coordinate space which is the three-dimensional coordinate space based on the measuring device 8g). The object to be measured includes, for example, at least one of the beam irradiation device 1f, the sample W, and the stage 22. Therefore, the measuring device 8g measures, for example, the position of at least one of the beam irradiation device 1f, the sample W, and the stage 22.

In particular, in the seventh embodiment, the measuring device 8g measures the positions of the surfaces of the two measurement objects facing each other (that is, the positions of the surfaces in the measurement coordinate space which is the three-dimensional coordinate space) (in other words, the positions of the surfaces). To detect). For example, when the stage 22 does not hold the sample W, the injection surface 12LS of the beam irradiation device 1f and the holding surface HS of the stage 22 (that is, the surface of the stage 22 that actually holds the sample W) face each other. .. Therefore, when the stage 22 does not hold the sample W, the measuring device 8g measures the positions of the injection surface 12LS and the holding surface HS, respectively. On the other hand, for example, when the stage 22 holds the sample W, the injection surface 12LS of the beam irradiation device 1 and the surface WSu of the sample W face each other. Therefore, the measuring device 8g measures the positions of the injection surface 12LS and the surface WSu when the stage 22 holds the sample W.

When the position of the surface (hereinafter referred to as "measurement surface") in the measurement coordinate space is known, the posture of the measurement surface in the measurement coordinate space (for example, the normal of the measurement surface extends with respect to a certain reference plane). Information about the direction) is revealed. Therefore, measuring the position of the measuring surface can be regarded as equivalent to measuring the posture of the measuring surface. Further, when the position of the measurement surface in the measurement coordinate space is known, the shape of the measurement surface in the measurement coordinate space is known. Therefore, measuring the position of the measuring surface can be regarded as equivalent to measuring the shape of the measuring surface.

When the positions of the surfaces of the two measurement objects facing each other are measured, the positional relationship between the surfaces of the two measurement objects facing each other becomes clear. Therefore, it can be said that the measuring device 8g measures the positional relationship between the surfaces of the two measurement objects facing each other. For example, when the stage 22 does not hold the sample W, it can be said that the measuring device 8g measures the positional relationship between the injection surface 12LS and the holding surface HS. On the other hand, for example, when the stage 22 holds the sample W, it can be said that the measuring device 8g measures the positional relationship between the injection surface 12LS and the surface WSu.

The measurement result of the measuring device 8g is output to the control device 4. The control device 4 performs a position control operation for controlling the positional relationship between the two measurement objects (that is, the positional relationship between the surfaces of the two measurement objects facing each other) based on the measurement result of the measurement device 8g. .. That is, the control device 4 performs a position control operation for controlling the positional relationship between the two measurement objects by moving at least one of the two measurement objects based on the measurement result of the measurement device 8g.

As described above, the two measurement objects include the beam irradiation device 1f and the stage 22. Therefore, the control device 4 performs a position control operation for controlling (that is, changing) the positional relationship between the beam irradiation device 1f and the stage 22. When the positional relationship between the beam irradiation device 1f and the stage 22 changes, the positional relationship between the injection surface 12LS of the beam irradiation device 1f and the holding surface HS of the stage 22 also changes. Therefore, the operation of controlling the positional relationship between the beam irradiation device 1f and the stage 22 can be regarded as equivalent to the operation of controlling the positional relationship between the injection surface 12LS and the holding surface HS. Further, when the stage 22 holds the sample W, the operation of controlling the positional relationship between the beam irradiation device 1f and the stage 22 is the positional relationship between the beam irradiation device 1 and the sample W (particularly, the injection surface 12LS). It can be regarded as equivalent to the operation of controlling (the positional relationship between the sample W and the surface WSu of the sample W). Therefore, when the stage 22 holds the sample W, the control device 4 can control the positional relationship between the beam irradiation device 1f and the sample W by performing a position control operation.

The positional relationship between the beam irradiation device 1f and the stage 22 and the positional relationship between the beam irradiation device 1f and the sample W change when at least one of the beam irradiation device 1f and the stage 22 moves. Therefore, the control device 4 moves at least one of the beam irradiation device 1f and the stage 22 to control the positional relationship between the beam irradiation device 1f and the stage 22 and the positional relationship between the beam irradiation device 1 and the sample W. In this case, the control device 4 controls the stage drive system 23 so that the electron beam EB is irradiated to the desired position of the surface WSu and the beam passing space SPb3 is set based on the measurement result of the measuring device 8g. The stage 22 may be moved along the XY plane. The control device 4 controls the stage drive system 23 so that the distance D between the surface WSu of the sample W and the injection surface 12LS of the beam irradiation device 1f becomes a desired distance D_target based on the measurement result of the measuring device 8g. Then, the stage 22 may be moved along the Z axis. Based on the measurement result of the measuring device 8g, the control device 4 may control the position adjusting system 14g so that the interval D becomes the desired interval D_target, and move the beam irradiation device 1 along the Z axis. The control device 4 controls the stage drive system 23 so that the surface WSu of the sample W is parallel to the injection surface 12LS of the beam irradiation device 1f based on the measurement result of the measuring device 8g, and controls the stage drive system 23 in the θX direction and θY. The stage 22 may be moved along at least one of the directions and the θZ direction. Based on the measurement result of the measuring device 8g, the control device 4 controls the position adjusting system 14g so that the surface WSu is parallel to the injection surface 12LS, and the beam is along at least one of the θX direction and the θY direction. The irradiation device 1 may be moved.

As described above, the state in which the surface WSu is parallel to the injection surface 12LS is parallel to the datum plane and only a desired distance when either the injection surface 12LS or the surface WSu is designated as the datum plane. This corresponds to a state in which either the injection surface 12LS or the surface WSu is accommodated between two distant virtual surfaces. Further, the desired distance is a value smaller than the desired interval D_taget (for example, a value of _target 1/10 or less of the desired interval D). Considering that the measurement result of the measuring device 8g is used to make the surface WSu parallel to the injection surface 12LS, the measuring device 8g sets the position of the measurement object at a desired distance (that is, from a desired interval D_target). It may be measured with a small distance and with an accuracy equivalent to, for example, 1/10 or less of _target of the desired interval D). As a result, the control device 4 has at least the beam irradiation device 1f and the stage 22 so that the interval D becomes the desired interval D_target and the surface WSu is parallel to the injection surface 12LS based on the measurement result of the measuring device 8g. One can be moved.

In order to measure the position of the object to be measured, the measuring device 8g may include, for example, 81g of a plurality of distance sensors (in other words, a length measuring sensor) capable of measuring the distance to the object to be measured. The distance sensor 81g irradiates the measurement object with the measurement light ML and detects the reflected light of the measurement light ML from the measurement object to measure the distance from the distance sensor 81g to the measurement object. This is a type of distance sensor. However, as the distance sensor 81g, another type of distance sensor may be used. As described above, since the measuring device 8g measures the position of the measurement object in the three-dimensional measurement coordinate space, the measuring device 8g measures at least three distances to the measurement target at least three places. Includes 81 g of distance sensor. However, the measuring device 8g may measure the position of the object to be measured by any measuring method. For example, the measuring device 8g may measure the position of the measurement target based on the shape of the beam spot of the measurement light ML on the surface of the measurement target. In this case, the beam spot becomes larger as the object to be measured moves away from the focus position of the measurement light ML, and the shape of the beam spot becomes ideal as the object to be measured tilts with respect to the optical axis of the measuring device 8 g. The measuring device 8g can measure the position of the object to be measured based on the shape of the beam spot of the measurement light ML because it deviates from the typical shape (for example, a perfect circular shape).

The measuring device 8 g (in the example shown in FIG. 20, the distance sensor 81 g, the same applies hereinafter) was fixed at a fixed position with respect to the beam irradiation device 1f (particularly, with respect to the differential exhaust system 12f provided with the injection surface 12LS). Position, the same below). That is, the measuring device 8g is arranged at a position where the positional relationship with respect to the beam irradiating device 1f is fixed (that is, does not change). In the example shown in FIG. 20, the measuring device 8g is arranged on the flange member 13 of the beam irradiation device 1f, but may be arranged at other positions. When the measuring device 8g is arranged at a fixed position with respect to the beam irradiating device 1f, the positions of the beam irradiating device 1f and the measuring device 8g even if the beam irradiating device 1f is moved by the position adjusting system 14g. The relationship does not change. That is, the position of the beam irradiation device 1f in the measurement coordinate space based on the measurement device 8g does not change. Therefore, if the position of the beam irradiating device 1f is once measured by the measuring device 8g, even if the beam irradiating device 1f is moved by the position adjusting system 14g, the control device 4 will move the beam irradiating device to the measuring device 8g. The position of the beam irradiation device 1f in the measurement coordinate space can be specified without having to measure the position of 1f again.

When the measuring device 8g is arranged at a fixed position with respect to the beam irradiating device 1f, the origin of the measuring coordinate space is the position related to the beam irradiating device 1f (particularly, the differential exhaust provided with the injection surface 12LS). The position related to the system 12f) may be set. For example, the origin of the measurement coordinate space may be set to the beam ejection port 1232 formed on the ejection surface 12LS. However, the origin of the measurement coordinate space may be set at a position different from the position related to the beam irradiation device 1f. For example, the origin of the measurement coordinate space may be set at a position related to the stage device 2 (for example, a position related to the surface plate 21). For example, the origin of the measurement coordinate space may be set at a position related to the support frame 3.

(7-2) Position control operation Subsequently, based on the measurement result of the measuring device 8g, the positional relationship between the beam irradiation device 1f and the stage 22 (furthermore, the positional relationship between the beam irradiation device 1f and the sample W, the same applies hereinafter. ) Will be further described. As described above, in the position control operation, (i) the electron beam EB is irradiated to the desired position of the surface WSu of the sample W, the beam passage space SPb3 is set (that is, the vacuum region VSP is formed), and (ii). This is an operation of controlling the positional relationship between the beam irradiation device 1f and the stage 22 so that the interval D becomes the desired interval D_taget and the surface WSu is parallel to the (iii) injection surface 12LS. In particular, the operation of controlling the positional relationship between the beam irradiation device 1f and the stage 22 so that the interval D becomes the desired interval D_taget and the surface WSu is parallel to the injection surface 12LS will be described below. The "control of the positional relationship between the beam irradiation device 1f and the stage 22" in the present embodiment is the position of the beam irradiation device 1f and the stage 22 in the direction along at least one of the X-axis, the Y-axis, and the Z-axis. Not only the relationship control but also the control of the positional relationship between the beam irradiation device 1f and the stage 22 in at least one of the θX direction, the θY direction and the θZ direction (that is, the control of the posture of at least one of the beam irradiation device 1f and the stage 22). ) Is also included.

One purpose of controlling the positional relationship between the beam irradiation device 1f and the stage 22 so that the interval D becomes a desired interval D_target is to determine the degree of vacuum of the vacuum region VSS formed between the beam irradiation device 1f and the sample W. It is to maintain it properly. Specifically, when the interval D becomes larger than the desired interval D_target, the degree of vacuum of the vacuum region VSP formed between the beam irradiation device 1f and the sample W may decrease. Therefore, the scanning electron microscope SEMg may not be able to form a vacuum region VSP having an appropriate degree of vacuum between the beam irradiation device 1f and the sample W. As a result, the scanning electron microscope SEMg may not be able to properly irradiate the sample W with the electron beam EB via the vacuum region VSP. Therefore, the control device 4 sets the beam irradiation device 1f so that the interval D is a desired interval D_stage capable of forming a vacuum region VSP with an appropriate degree of vacuum between the beam irradiation device 1f and the sample W. The positional relationship between the device and the stage 22 is controlled.

One purpose of controlling the positional relationship between the beam irradiation device 1f and the stage 22 so that the interval D becomes a desired interval D_target is to prevent contact (in other words, collision) between the beam irradiation device 1f and the sample W. is there. Specifically, in the stage 22, as shown in FIG. 21A, both the holding surface HS of the stage 22 and the injection surface 12LS of the beam irradiation device 1f are usually parallel to the XY plane, and the injection surface 12LS and the injection surface 12LS The sample W is held in a state where the surface WSu of the sample W is parallel to both of the holding surfaces HS, and then moves along the XY plane. For example, when the front surface WSu of the sample W and the back surface (that is, the surface opposite to the front surface WSu and facing the holding surface HS) are parallel, the stage 22f is shown in FIG. 21 (a). The sample W can be easily held in the state shown. In this case, even if the interval D is not adjusted according to the movement of the stage 22 in the XY plane, the interval D changes significantly (in other words, unintentionally) due to the movement of the stage 22. There is no. On the other hand, as shown in FIG. 21B, the stage 22 may move along the XY plane while holding the sample W in a state where the surface WSu is not parallel to the injection surface 12LS. .. For example, if the front surface WSu and the back surface of the sample W are not parallel, the stage 22 may hold the sample W in the state shown in FIG. 21 (b). Alternatively, for example, if at least one of the injection surface 12LS and the holding surface HS is not parallel to the XY plane, the stage 22 may hold the sample W in a state where the surface WSu is not parallel to the injection surface 12LS. is there. In this case, if the interval D is not adjusted according to the movement of the stage 22 in the XY plane, the interval D changes significantly (in other words, unintentionally) due to the movement of the stage 22 in the XY plane. There is a possibility that it will end up. As a result, the beam irradiation device 1f and the sample W may come into contact with each other. On the other hand, when the interval D is adjusted according to the movement of the stage 22 in the XY plane (that is, the interval D is adjusted to be the desired interval D_taget), the stage 22 moves in the XY plane. However, the interval D does not change significantly (in other words, unintentionally). As a result, contact between the beam irradiation device 1f and the sample W can be prevented.

One purpose of controlling the positional relationship between the beam irradiation device 1f and the stage 22 so that the surface WSu is parallel to the injection surface 12LS is to prevent contact between the beam irradiation device 1f and the sample W. This is because, as already described with reference to FIG. 21B, when the stage 22 holds the sample W in a state where the surface WSu is not parallel to the injection surface 12LS, the stage 22 moves in the XY plane. This is because there is a possibility that the beam irradiation device 1f and the sample W come into contact with each other. On the other hand, if the stage 22 holds the sample W in a state where the surface WSu is parallel to the injection surface 12LS, even if the stage 22 moves in the XY plane, the beam irradiation device 1f and the sample W come into contact with each other. The possibility of closing is relatively small.

In the seventh embodiment, the position control operation is performed after the first control operation (so-called initial operation) performed before the stage 22 holds the sample W and after the first control operation is performed, and the stage 22. Includes a second control operation performed after holding the sample W. The first and second control operations are performed, for example, before the scanning electron microscope SEMg irradiates the sample W with the electron beam EB to measure the state of the sample W, but as will be described later (for example, the eleventh). (Refer to the embodiment), at least one of the first and second control operations is performed during at least a part of the period during which the scanning electron microscope SEMg irradiates the sample W with the electron beam EB and measures the state of the sample W. You may. Hereinafter, the first control operation and the second control operation will be described in order.

(7-2-1) First Control Operation First, the first control operation corresponding to the position control operation performed before the stage 22 holds the sample W will be described with reference to FIGS. 22 to 28. FIG. 22 is a flowchart showing the flow of the first control operation corresponding to the position control operation performed before the stage 22 holds the sample W. Each of FIGS. 23 to 26 is a cross-sectional view showing how one step of the first control operation is being performed. FIG. 27 is a schematic view showing the position of the surface WSuv of the virtual sample Wv estimated from the position of the holding surface HS of the stage 22. FIG. 28A shows the positional relationship between the injection surface 12LS of the beam irradiation device 1f and the holding surface HS of the stage 22 and the surface WSuv of the virtual sample Wv before moving at least one of the beam irradiation device 1f and the stage 22. FIG. 28 (b) is a schematic view showing the injection surface 12LS of the beam irradiation device 1f after moving at least one of the beam irradiation device 1f and the stage 22, the holding surface HS of the stage 22, and the virtual sample Wv. It is a schematic diagram which shows the positional relationship of the surface WSuv of.

As shown in FIGS. 22 and 23, first, the reference member BM is arranged on the injection surface 12LS of the beam irradiation device 1f (step S11). The reference member BM includes a reference surface BS. The reference plane BS is a plane whose flatness is equal to or less than a predetermined value. In the seventh embodiment, the "flatness of the surface C" means the distance between the two virtual planes when the surface C is sandwiched between two virtual planes parallel to each other. .. The predetermined value may be a value smaller than the desired interval D_target described above. For example, the predetermined value may be a value of 1/10 or less of the desired interval D_taget described above. The reference surface BS is larger than the injection surface 12LS. That is, the reference surface BS can include at least a part of the injection surface 12LS. An example of such a reference member BM is a glass substrate or a silicon substrate provided with a relatively high-precision polished surface as a reference surface BS that can be used as a reference surface BS.

The reference member BM is arranged on the injection surface 12LS so that a part of the reference surface BS and at least a part of the injection surface 12LS are in contact (in other words, in close contact with each other). That is, the reference member BM is arranged on the injection surface 12LS so that a part of the reference surface BS which is a plane facing upward and at least a part of the injection surface 12LS which is a plane facing downward coincide with each other. Note that FIG. 23 shows an example in which the reference member BS is arranged on the injection surface 12LS so that a part of the reference surface BS and the entire injection surface 12LS coincide with each other. Since the reference surface BS having a flatness of a predetermined value or less comes into contact with the injection surface 12LS, the injection surface 12LS may also be a flat surface having a flatness of a predetermined value or less.

Since the reference surface BS faces upward and is larger than the injection surface 12LS, the reference member BM has the measurement light ML from the distance sensor 81g fixed to the beam irradiation device 1f located above the reference member BM as the reference surface. It is arranged on the injection surface 12LS so that the BS can be irradiated. Conversely, the reference member BM has a size such that the measurement light ML from the distance sensor 81 g can irradiate the reference surface BS with the reference member BM arranged on the injection surface 12LS.

After that, as shown in FIGS. 22 and 24, the measuring device 8g measures the position of the reference surface BS of the reference member BM (step S12). Specifically, as shown in FIG. 24, the distance sensor 81g irradiates the reference surface BS with the measurement light ML and detects the reflected light of the measurement light ML from the reference surface BS. Therefore, the distance sensor 81g is arranged at a position where the measurement light ML can be irradiated to the reference surface BS of the reference member BM arranged on the injection surface 12LS. The measurement result of the distance sensor 81 g is output to the control device 4. The control device 4 specifies the distance between each distance sensor 81g and the surface portion of the reference surface BS irradiated with the measurement light ML from each distance sensor 81g based on the measurement result of each distance sensor 81g. Since the measuring device 8g includes at least three distance sensors 81g, the control device 4 has at least a first distance, a second distance, between the first distance sensor 81g and the first surface portion of the reference plane BS. The second distance between the distance sensor 81g and the second surface portion of the reference surface BS and the third distance between the third distance sensor 81g and the third surface portion of the reference surface BS are specified. .. As a result, the control device 4 can specify the position of the reference plane BS (that is, the position of each part of the reference plane BS in the measurement coordinate space). In other words, the control device 4 can specify an equation indicating the reference plane BS in the measurement coordinate space.

After that, as shown in FIG. 22, the control device 4 estimates the position of the injection surface 12LS of the beam irradiation device 1 (step S13). Specifically, as described above, the reference member BM is arranged on the injection surface 12LS so that a part of the reference surface BS and at least a part of the injection surface 12LS are in contact with each other. Therefore, the operation of measuring the position of the reference surface BS can be regarded as substantially equivalent to the operation of measuring the position of the injection surface 12LS. Therefore, the control device 4 uses the position of the reference surface BS specified in step S12 as the position of the injection surface 12LS.

However, when the measuring device 8g includes at least three distance sensors 81g, the position of the reference plane BS specified in step S12 is substantially the position of the virtual plane including the reference plane BS (that is,). , Corresponds to the equation) showing the virtual plane including the reference plane BS in the measurement coordinate space. That is, the position of the injection surface 12LS specified in step S13 is substantially the position of the virtual plane including the injection surface 12LS (that is, the position of the virtual plane including the injection surface 12LS) in the measurement coordinate space. Corresponds to the equation shown in. However, considering that the purpose of the position control operation is to make the distance D between the injection surface 12LS and the surface WSu a desired distance D_taget and to make the injection surface 12LS and the surface WSu parallel, in step S12. It is sufficient to specify the position of the virtual plane including the reference plane BS, and in step S13, it is sufficient to specify the position of the virtual plane containing the injection surface 12LS. This is because if the position of the virtual plane including the injection surface 12LS is specified, the control device 4 can specify the interval D and the parallelism of the injection surface 12LS with respect to the surface WSu (that is, the surface WSu). This is because it is possible to specify the amount of deviation of either the surface WSu and the injection surface 12LS with respect to the datum plane which is one of the injection surfaces 12LS).

As described above, even when it is difficult for the measuring device 8g to directly measure the position of the injection surface 12LS according to the positional relationship between the injection surface 12LS and the measuring device 8g, the scanning electron microscope SEMg is a reference. The position of the injection surface 12LS can be specified by using the member BM. In the scanning electron microscope SEMg shown in FIG. 20, since it is difficult for the distance sensor 81 g to directly irradiate the ejection surface 12LS with the measurement light ML, the measuring device 8 g directly measures the position of the ejection surface 12LS. Is difficult. Therefore, in the scanning electron microscope SEMg, the position of the injection surface 12LS is specified by using the reference member BM.

After that, as shown in FIG. 23, the reference member BM arranged on the injection surface 12LS is removed from the injection surface 12LS (step S14).

After that (or prior to the processing from step S11 to step S14), as shown in FIGS. 22 and 25, the measuring device 8g measures the position of the holding surface HS of the stage 22 (step S15). Specifically, as shown in FIG. 25, the distance sensor 81g irradiates the holding surface HS with the measurement light ML and detects the reflected light of the measurement light ML from the holding surface HS. Therefore, the distance sensor 81g is arranged at a position where the measurement light ML can be irradiated to the holding surface HS. The measurement result of the distance sensor 81 g is output to the control device 4. The control device 4 specifies the distance between each distance sensor 81g and the surface portion of the holding surface HS irradiated with the measurement light ML from each distance sensor 81g, based on the measurement result of each distance sensor 81g. As a result, the control device 4 performs the position of the holding surface HS (that is, each part of the holding surface HS in the measurement coordinate space) in the same manner as the method of specifying the position of the reference surface BS in step S12 described above. The position) can be specified. In other words, the control device 4 can specify an equation indicating the holding surface HS in the measurement coordinate space. Since the measuring device 8g is arranged at a fixed position with respect to the beam irradiating device 1f, the positional relationship between the beam irradiating device 1f and the measuring device 8g when the measuring device 8g measures the position of the holding surface HS. Is the same as the positional relationship between the beam irradiation device 1f and the measuring device 8g when the measuring device 8g measures the position of the injection surface 12LS.

After that, as shown in FIGS. 22 and 26, the control device 4 estimates the position of the surface WSuv of the virtual sample Wv on the assumption that the stage 22 holds the virtual sample Wv (as shown in FIGS. 22 and 26). Step S16). The virtual sample Wv is, for example, a sample having the same shape and size as the ideal sample W (in other words, the sample W conforming to the standard). In this case, since the surface WSu is flat, the surface WSuv of the virtual sample Wv is also flat. Further, the surface WSuv of the virtual sample Wv is, for example, parallel to the holding surface HS. Therefore, as shown in FIG. 26, the surface WSuv corresponds to a plane obtained by shifting the holding surface HS along the Z-axis direction (that is, the thickness direction of the virtual sample Wv). Therefore, as shown in FIG. 27, the control device 4 sets the position of the holding surface HS specified in step S15 by a distance corresponding to the thickness of the virtual sample Wv (that is, the size in the Z-axis direction) Whv. The position of the virtual plane obtained by shifting in the Z-axis direction is specified, and the specified position is treated as the position of the surface WSuv.

However, when the measuring device 8g includes at least three distance sensors 81g, the position of the holding surface HS specified in step S15 is substantially the position of the virtual plane including the holding surface HS ( That is, it corresponds to an equation) indicating a virtual plane including the holding surface HS in the measurement coordinate space. That is, the position of the surface WSuv of the virtual sample Wv specified in step S16 is substantially the position of the virtual plane containing the surface WSuv (that is, the virtual plane containing the surface WSuv). Corresponds to the equation shown in the measurement coordinate space). However, considering that the purpose of the position control operation is to make the distance D between the injection surface 12LS and the surface WSu a desired distance D_taget and to make the injection surface 12LS and the surface WSu parallel, in step S15. It is sufficient to specify the position of the virtual plane including the holding surface HS, and in step S16, it is sufficient to specify the position of the virtual plane containing the surface WSuv. This is because if the position of the virtual plane containing the surface WSuv is specified, the control device 4 can specify the distance D'between the surface WSuv and the injection surface 12LS, and the surface WSuv and the surface WSuv. This is because the parallelism with the injection surface 12LS (that is, the amount of deviation of either the surface WSuv or the injection surface 12LS with respect to the datum plane which is one of the surface WSuv and the injection surface 12LS) can be specified.

After that, as shown in FIG. 22, in the control device 4, the distance D'between the surface WSuv and the injection surface 12LS becomes a desired distance D_stage, and the surface WSuv is parallel to the injection surface 12LS. The positional relationship between the beam irradiation device 1f and the stage 22 is controlled (step S17). Specifically, the control device 4 determines the positional relationship between the injection surface 12LS and the surface WSuv in the measurement coordinate space from the position of the injection surface 12LS specified in step S13 and the position of the surface WSuv specified in step S16. Can be identified. That is, the control device 4 can specify the distance D'between the surface WSuv and the injection surface 12LS and the parallelism between the injection surface 12LS and the surface WSuv. As a result, when the interval D'is not the desired interval D_stage as shown in FIG. 28 (a), the control device 4 sets the interval D'to be the desired interval D_stage as shown in FIG. 28 (b). (That is, at least one of the stage drive system 23 and the position adjustment system 14 g is controlled so as to approach the desired interval D_taget) to control the positional relationship between the stage 22 and the beam irradiation device 1f. Further, when the injection surface 12LS and the surface WSuv are not parallel as shown in FIG. 28 (a), in the control device 4, the injection surface 12LS and the surface WSuv are parallel as shown in FIG. 28 (b). (That is, so as to approach the parallel state), at least one of the stage drive system 23 and the position adjustment system 14g is controlled to control the positional relationship between the stage 22 and the beam irradiation device 1f. At this time, the control device 4 controls the positional relationship between the stage 22 and the beam irradiation device 1f so that the injection surface 12LS and the surface WSuv (furthermore, the holding surface HS) are parallel to the XY plane. May be good.

The measuring device 8g may measure the position of the holding surface HS during at least a part of the period in which the control device 4 controls the positional relationship between the stage 22 and the beam irradiation device 1f. In this case, the control device 4 specifies the position of the surface WSuv based on the measurement result of the measuring device 8g, and whether or not the interval D'is the desired interval D_target based on the specified position of the surface WSuv, and , It may be determined whether or not the surface WSuv is parallel to the injection surface 12LS. In order to make this determination, the control device 4 also needs to specify the position of the injection surface 12LS. However, since the measuring device 8g is arranged at a fixed position with respect to the beam irradiating device 1f as described above, even if the control device 4 controls the positional relationship between the stage 22 and the beam irradiating device 1f, the measurement is performed. The position of the beam irradiation device 1f in the measurement coordinate space based on the device 8g does not change. Therefore, the control device 4 can specify the position of the injection surface 12LS in the measurement coordinate space without having the measuring device 8g measure the position of the injection surface 12LS of the beam irradiation device 1f again.

By the first control operation described above, the interval D'becomes the desired interval D_taget, and the surface WSuv becomes parallel to the injection surface 12LS (furthermore, the holding surface HS becomes parallel to the injection surface 12LS). .. As a result, when the sample W actually held by the stage 22 is a sample having the same shape and the same size as the virtual sample Wv (that is, an ideal sample), the stage 22 has an interval D. Is the desired interval D_stage, and the sample W can be held in a state where the surface WSu is parallel to the injection surface 12LS. On the other hand, when the sample W actually held by the stage 22 is a sample that does not have the same shape and / or the same size as the virtual sample Wv, the interval D of the stage 22 is the desired interval D_target, and It is not always possible to hold the sample W in a state where the surface WSu is parallel to the injection surface 12LS. Therefore, the control device 4 performs the second control operation described below, and after the stage 22 actually holds the sample W, the interval D becomes the desired interval D_taget, and the surface WSuv is set with respect to the injection surface 12LS. The positional relationship between the stage 22 and the beam irradiation device 1f is controlled so as to be parallel.

It is possible that the interval D'is not the desired interval D_taget and / or the surface WSuv is not parallel to the injection surface 12LS until the first control operation is completed. Therefore, when the stage 22 moves along the XY plane (that is, along at least one of the X-axis and the Y-axis) during at least a part of the period during which the first control operation is performed, FIG. 21 (b) shows. As shown, the beam irradiator 1f and the stage 22 may come into contact with each other. Therefore, the control device 4 does not move the stage 22 along the XY plane during the period during which the first control operation is performed. However, if necessary, the control device 4 may move the stage 22 along the XY plane during at least a part of the period during which the first control operation is performed.

(7-2-2) Second Control Operation Subsequently, with reference to FIGS. 29 to 31 (b), a second control operation corresponding to the position control operation performed after the stage 22 holds the sample W will be described. To do. FIG. 29 is a flowchart showing the flow of the second control operation corresponding to the position control operation performed after the stage 22 holds the sample W. FIG. 30 is a cross-sectional view showing how one step of the second control operation is being performed. FIG. 31A is a schematic view showing the positional relationship between the injection surface 12LS of the beam irradiation device 1f and the holding surface HS of the stage 22 and the surface WSu of the sample W before moving at least one of the beam irradiation device 1f and the stage 22. 31 (b) shows the positional relationship between the injection surface 12LS of the beam irradiation device 1 after moving at least one of the beam irradiation device 1f and the stage 22, the holding surface HS of the stage 22, and the surface WSu of the sample W. It is a schematic diagram which shows.

As shown in FIG. 29, first, the stage 22 holds the sample W (step S21). Then, as shown in FIGS. 29 and 30, the measuring device 8g was held by the stage 22 before the scanning electron microscope SEMg irradiated the sample W with the electron beam EB and started measuring the state of the sample W. The position of the surface WSu of the sample W is measured (step S22). Specifically, as shown in FIG. 30, the distance sensor 81g irradiates the surface WSu with the measurement light ML and detects the reflected light of the measurement light ML from the surface WSu. Therefore, the distance sensor 81g is arranged at a position where the measurement light ML can be irradiated to the surface WSu. The measurement result of the distance sensor 81 g is output to the control device 4. The control device 4 specifies the distance between each distance sensor 81g and the surface portion of the surface WSu irradiated with the measurement light ML from each distance sensor 81g, based on the measurement result of each distance sensor 81g. As a result, the control device 4 performs the position of the surface WSu (that is, each part of the surface WSu in the measurement coordinate space) in the same manner as the method of specifying the position of the reference surface BS in step S12 of FIG. 22 described above. Position) can be specified. In other words, the control device 4 can specify an equation indicating the surface WSu in the measurement coordinate space.

After that, as shown in FIG. 29, the control device 4 makes a beam so that the distance D between the surface WSu and the injection surface 12LS becomes a desired distance D_stage and the surface WSu is parallel to the injection surface 12LS. The positional relationship between the irradiation device 1f and the stage 22 is controlled (step S23). Specifically, since the measuring device 8g is arranged at a fixed position with respect to the beam irradiating device 1f as described above, the control device 4 is located on the measuring device 8g at the position of the injection surface 12LS of the beam irradiating device 1f. The position of the injection surface 12LS in the measurement coordinate space can be specified without having to measure again. That is, the control device 4 can use the position of the injection surface 12LS specified in the first control operation as it is in the second control operation. Therefore, the control device 4 specifies the positional relationship between the injection surface 12LS and the surface WSu in the measurement coordinate space from the position of the injection surface 12LS specified in the first control operation and the position of the surface WSu specified in step S22. can do. That is, the control device 4 can specify the distance D between the surface WSu and the injection surface 12LS and the parallelism between the injection surface 12LS and the surface WSu. As a result, when the interval D is not the desired interval D_stage as shown in FIG. 31 (a), the control device 4 sets the interval D to the desired interval D_stage (that is, as shown in FIG. 31 (b)). , At least one of the stage drive system 23 and the position adjustment system 14 g is controlled so as to approach the desired interval D_taget) to control the positional relationship between the stage 22 and the beam irradiation device 1f. Further, when the injection surface 12LS and the surface WSu are not parallel as shown in FIG. 31A, in the control device 4, the injection surface 12LS and the surface WSu are parallel as shown in FIG. 31B. (That is, so as to approach the parallel state), at least one of the stage drive system 23 and the position adjustment system 14g is controlled to control the positional relationship between the stage 22 and the beam irradiation device 1f. At this time, the control device 4 may control the positional relationship between the stage 22 and the beam irradiation device 1f so that the injection surface 12LS and the surface WSu are parallel to the XY plane.

The measuring device 8g may measure the position of the surface WSu during at least a part of the period in which the control device 4 controls the positional relationship between the stage 22 and the beam irradiation device 1f. In this case, the control device 4 determines whether or not the interval D is the desired interval D_taget and whether or not the surface WSu is parallel to the injection surface 12LS based on the measurement result of the measuring device 8g. You may. In order to make the above-mentioned determination, the control device 4 also needs to specify the position of the injection surface 12LS, but the control device 4 does not have the measuring device 8g measure the position of the injection surface 12LS again. As described above, the position of the injection surface 12LS in the space can be specified.

By the second control operation described above, after the stage 22 holds the sample W, the interval D becomes the desired interval D_taget, and the surface WSu becomes parallel to the injection surface 12LS. As a result, even when the sample W actually held by the stage 22 is a sample that does not have the same shape and / or the same size as the virtual sample Wv, the interval D of the stage 22 becomes the desired interval D_taget. Moreover, the sample W can be held in a state where the surface WSu is parallel to the injection surface 12LS. After that, the scanning electron microscope SEMg moves the stage 22 along the XY plane (that is, the sample W) in a state where the interval D becomes the desired interval D_target and the surface WSu is parallel to the injection surface 12LS. The state of the sample W can be measured by irradiating the sample W with the electron beam EB (while moving the sample W). As a result, the scanning electron microscope SEMg appropriately maintains the degree of vacuum of the vacuum region VSP formed between the beam irradiation device 1f and the sample W, and prevents contact between the beam irradiation device 1f and the sample W. , The state of the sample W can be measured.

It is possible that the interval D is not the desired interval D_taget and / or the surface WSu is not parallel to the injection surface 12LS until the second control operation is completed. Therefore, when the stage 22 moves along the XY plane (that is, along at least one of the X-axis and the Y-axis) during at least a part of the period during which the second control operation is performed, FIG. 21B shows. As shown, there is a possibility that the beam irradiation device 1f and the sample W come into contact with each other. Therefore, the control device 4 does not move the stage 22 along the XY plane during the period during which the second control operation is performed. However, if necessary, the control device 4 may move the stage 22 along the XY plane during at least a part of the period during which the second control operation is performed.

Further, in the above description, since it is difficult for the measuring device 8g to directly measure the position of the injection surface 12LS, the scanning electron microscope SEMg uses the reference member BM to measure the position of the injection surface 12LS. Is specified. However, when the measuring device 8g can directly measure the position of the injection surface 12LS (for example, the distance sensor 81g can irradiate the injection surface 12LS with the measurement light ML), a scanning electron microscope. The SEMg may specify the position of the injection surface 12LS without using the reference member BM.

Further, in the above description, the measuring device 8g can directly measure the positions of the holding surface HS and the surface WSu (for example, the distance sensor 81g directly measures the measurement light ML on the holding surface HS and the surface WSu). The scanning electron microscope SEMg identifies the positions of the holding surface HS and the surface WSu without using the reference member BM because it can be irradiated). However, when it is difficult for the measuring device 8g to directly measure the positions of at least one of the holding surface HS and the surface WSu, the scanning electron microscope SEMg uses the reference member BM to measure the holding surface HS and the surface WSu. At least one position of the surface WSu may be specified. Specifically, for example, in the scanning electron microscope SEMg, the reference member BM is arranged on the holding surface HS so that at least a part of the holding surface HS and at least a part of the reference surface BS of the reference member BM are in contact with each other. The position of the reference surface BS may be measured, and the measured position of the reference surface BS may be treated as the position of the holding surface HS. In this case, the reference surface BS may be a surface that can include at least a part of the holding surface HS. For example, in the scanning electron microscope SEMg, the reference member BM is arranged on the surface WSu so that at least a part of the surface WSu and at least a part of the reference surface BS of the reference member BM are in contact with each other, and the position of the reference surface BS is measured. Then, the measured position of the reference surface BS may be treated as the position of the surface WSu. In this case, the reference surface BS may be a surface that can include at least a part of the surface WSu. The reference member BM used for measuring the positions of the holding surface HS and the surface WSu may be the same as or different from the reference member BM used for measuring the position of the injection surface 12LS. Good.

Further, in the above description, the position of the injection surface 12LS of the beam irradiation device 1f is measured by the measuring device 8g during the period during which the position control operation is performed. However, since the measuring device 8g is arranged at a fixed position with respect to the beam irradiating device 1, the positional relationship between the beam irradiating device 1 and the measuring device 8g changes during the period during which the position control operation is performed. There is no. Therefore, before the position control operation is performed, the position of the injection surface 12LS is measured by the measuring device 8g, and the measurement result of the measuring device 8g (that is, information indicating the position of the injection surface 12LS) is provided in the control device 4. It may be stored in a storage device or the like. In this case, during the period in which the position control operation is performed, the control device 4 does not cause the measuring device 8g to measure the position of the injection surface 12LS, and the information indicating the position of the injection surface 12LS stored in the storage device. The position control operation may be performed based on.

Further, in the above description, in the seventh embodiment, the scanning electron microscope SEMg includes a beam irradiation device 1f in which the opening 126 is not formed. However, in the scanning electron microscope SEMg, instead of the beam irradiation device 1f, the beam irradiation device 1a in which the opening 126 is formed, the

beam irradiation device

1b or 1c in which the opening 126b is formed, and the aperture member 16d are arranged. The device 1d or the beam irradiation device 1e in which a plurality of openings 126e are formed may be provided. That is, with respect to the scanning electron microscope SEMg of the seventh embodiment, at least a part of the constituent requirements (particularly, the beam passing space) of the scanning electron microscope SEMa of the first embodiment to the scanning electron microscope SEMg of the fifth embodiment (particularly, the beam passing space). At least a part of the constituent requirements for controlling the degree of vacuum of at least a part of SPb) may be combined. In this case, the scanning electron microscope SEMg may control the degree of vacuum of at least a part of the beam passing space SPb and also control the interval D. Alternatively, the scanning electron microscope SEMg may control the degree of vacuum of at least a part of the beam passing space SPb by controlling the interval D, similarly to the scanning electron microscope SEMf of the sixth embodiment. The same applies to the scanning electron microscope SEMh of the eighth embodiment described later to the scanning electron microscope SEMk of the eleventh embodiment, which correspond to a modification of the scanning electron microscope SEMg of the seventh embodiment.

(8) Scanning electron microscope SEMh of the eighth embodiment
Subsequently, with reference to FIG. 32, the scanning electron microscope SEM of the eighth embodiment (hereinafter, the scanning electron microscope SEM of the eighth embodiment will be referred to as “scanning electron microscope SEMh”) will be described. FIG. 32 is a cross-sectional view showing the structure of the scanning electron microscope SEMh of the eighth embodiment.

As shown in FIG. 32, in the scanning electron microscope SEMh of the eighth embodiment, the position where the measuring device 8g is fixed with respect to the stage 22 as compared with the scanning electron microscope SEMg of the seventh embodiment described above. It differs in that it is located in. Other features of the scanning electron microscope SEMh may be the same as those of the scanning electron microscope SEMg.

The measuring device 8g is arranged at a position where the positional relationship with respect to the stage 22 is fixed (that is, does not change). In the example shown in FIG. 32, the measuring device 8g is arranged on the side surface of the stage 22, but may be arranged at other positions. When the measuring device 8g is arranged at a fixed position with respect to the stage 22, even if the stage 22 is moved by the stage drive system 23, the positional relationship between the stage 22 and the measuring device 8g does not change. .. That is, the position of the stage 22 in the measurement coordinate space based on the measuring device 8g does not change. Therefore, if the position of the stage 22 is once measured by the measuring device 8g, the control device 4 measures the position of the stage 22 again on the measuring device 8g even if the stage 22 is moved by the stage drive system 23. The position of the stage 22 in the measurement coordinate space can be specified without causing the stage 22 to be specified.

When the stage 22 holds the sample W, it can be said that the measuring device 8g is arranged at a position where the positional relationship with respect to the sample W is fixed (that is, does not change). When the measuring device 8g is arranged at a fixed position with respect to the sample W, even if the stage 22 holding the sample W is moved by the stage drive system 23, the sample W and the measuring device 8g The positional relationship does not change. That is, the position of the sample W in the measurement coordinate space with respect to the measuring device 8g does not change. Therefore, once the position of the sample W has been measured by the measuring device 8g, the control device 4 measures the position of the sample W again by the measuring device 8g even if the stage 22 is moved by the stage drive system 23. The position of the sample W in the measurement coordinate space can be specified without causing the sample W to be specified.

The scanning electron microscope SEMh can perform the first control operation shown in FIG. 22 in the same manner as the scanning electron microscope SEMg described above. However, in the eighth embodiment, when the measuring device 8g can directly measure the position of the injection surface 12LS, the scanning electron microscope SEMg is the reference member BM in steps S11 to S14 of FIG. The position of the injection surface 12LS may be specified without using. Further, when it is difficult for the measuring device 8g to directly measure the position of the holding surface HS, the scanning electron microscope SEMa placed the reference member BM on the holding surface HS in step S15 of FIG. The position of the holding surface HS may be specified above.

The scanning electron microscope SEMh can perform the second control operation shown in FIG. 29 in the same manner as the scanning electron microscope SEMg described above. However, in the eighth embodiment, when it is difficult for the measuring device 8g to directly measure the position of the surface WSu, the scanning electron microscope SEMh places the reference member BM on the surface in step S22 of FIG. The position of the surface WSu may be specified after being arranged on the WSu. Further, in the eighth embodiment, the scanning electron microscope SEMh causes the measuring device 8g to measure the position of the injection surface 12LS before performing step S23 in FIG. 29, and then measures the injection in step S23 in FIG. At least one position of the beam irradiation device 1f and the stage 22 so that the interval D becomes the desired interval D_taget and the surface WSu is parallel to the injection surface 12LS based on the position of the surface 12LS and the position of the surface WSu. To control.

As described above, the scanning electron microscope SEMh of the eighth embodiment can increase the degree of freedom in arranging the measuring device 8g while enjoying the same effect as the effect that can be enjoyed by the scanning electron microscope SEMg described above. it can.

In the eighth embodiment, since the measuring device 8g is arranged at a fixed position with respect to the stage 22, the positional relationship between the stage 22 and the measuring device 8g is changed during the period when the position control operation is performed. It doesn't change. Therefore, before the position control operation is performed, the position of the holding surface HS of the stage 22 is measured by the measuring device 8g, and the measurement result of the measuring device 8g (that is, information indicating the position of the holding surface HS) is the control device. It may be stored in a storage device or the like provided in 4. In this case, during the period in which the position control operation is performed, the control device 4 does not cause the measuring device 8g to measure the position of the holding surface HS, and the information indicating the position of the holding surface HS stored in the storage device. The position control operation may be performed based on.

(9) Scanning electron microscope SEMi of the ninth embodiment
Subsequently, with reference to FIG. 33, the scanning electron microscope SEM of the ninth embodiment (hereinafter, the scanning electron microscope SEM of the ninth embodiment will be referred to as “scanning electron microscope SEMi”) will be described. FIG. 33 is a cross-sectional view showing the structure of the scanning electron microscope SEMi of the ninth embodiment.

As shown in FIG. 33, in the scanning electron microscope SEMi of the ninth embodiment, as compared with the scanning electron microscope SEMg of the seventh embodiment described above, the measuring device 8g has both the beam irradiation device 1f and the stage 22. It differs in that it is placed in a non-fixed position with respect to. Other features of the scanning electron microscope SEMi may be the same as those of the scanning electron microscope SEMg.

The measuring device 8g is arranged at a position where the positional relationship with respect to the beam irradiation device 1f and the stage 22 is non-fixed (that is, may change). In the example shown in FIG. 33, the measuring device 8g is arranged on the support frame 3, but may be arranged at other positions. When the measuring device 8g is arranged at a non-fixed position with respect to the beam irradiating device 1f, when the beam irradiating device 1f is moved by the position adjusting system 14, the positional relationship between the beam irradiating device 1f and the measuring device 8g May change. That is, the position of the beam irradiation device 1f in the measurement coordinate space based on the measurement device 8g may change. Therefore, each time the beam irradiation device 1f is moved by the position adjustment system 14 during the period in which the position control operation is performed, the control device 4 causes the measuring device 8g to measure the position of the beam irradiation device 1f again, and the measuring device The position of the beam irradiation device 1f in the measurement coordinate space is specified based on the remeasurement result of 8 g. Similarly, when the measuring device 8g is arranged at a non-fixed position with respect to the stage 22, the positional relationship between the stage 22 and the measuring device 8g may change when the stage 22 is moved by the stage drive system 23. There is sex. That is, the position of the stage 22 in the measurement coordinate space based on the measuring device 8g may change. Therefore, each time the stage 22 is moved by the stage drive system 23 during the period in which the position control operation is performed, the control device 4 causes the measuring device 8g to measure the position of the stage 22 again, and the measuring device 8g is re-measured. Based on the measurement result, the position of the stage 22 in the measurement coordinate space is specified.

When the stage 22 holds the sample W, it can be said that the measuring device 8g is arranged at a position where the positional relationship with respect to the sample W is non-fixed (that is, may change). In this case, if the stage 22 holding the sample W moves, the positional relationship between the sample W and the measuring device 8g may change. That is, the position of the sample W in the measurement coordinate space with respect to the measuring device 8g may change. Therefore, each time the stage 22 moves during the period in which the position control operation is performed, the control device 4 causes the measuring device 8g to measure the position of the sample W again, and based on the measurement result of the measuring device 8g again. , The position of the sample W in the measurement coordinate space is specified.

The scanning electron microscope SEMi can perform the first control operation shown in FIG. 22 in the same manner as the scanning electron microscope SEMg described above. However, in the ninth embodiment, when the measuring device 8g can directly measure the position of the injection surface 12LS, the scanning electron microscope SEMi has the reference member BM in steps S11 to S14 of FIG. The position of the injection surface 12LS may be specified without using. Further, when it is difficult for the measuring device 8g to directly measure the position of the holding surface HS, the scanning electron microscope SEMi placed the reference member BM on the holding surface HS in step S15 of FIG. The position of the holding surface HS may be specified above.

The scanning electron microscope SEMi can perform the second control operation shown in FIG. 29 in the same manner as the scanning electron microscope SEMg described above. However, in the ninth embodiment, when it is difficult for the measuring device 8g to directly measure the position of the surface WSu, the scanning electron microscope SEMi puts the reference member BM on the surface in step S22 of FIG. The position of the surface WSu may be specified after being arranged on the WSu. Further, in the ninth embodiment, the scanning electron microscope SEMi causes the measuring device 8g to measure the position of the injection surface 12LS before performing step S23 in FIG. 29, and then measures the injection in step S23 in FIG. At least one position of the beam irradiation device 1f and the stage 22 so that the interval D becomes the desired interval D_taget and the surface WSu is parallel to the injection surface 12LS based on the position of the surface 12LS and the position of the surface WSu. To control.

As described above, the scanning electron microscope SEMi of the ninth embodiment can increase the degree of freedom in arranging the measuring device 8g while enjoying the same effect as the effect that the scanning electron microscope SEMg described above can enjoy. it can.

(10) Scanning electron microscope SEMj of the tenth embodiment
Subsequently, with reference to FIG. 34, the scanning electron microscope SEM of the tenth embodiment (hereinafter, the scanning electron microscope SEM of the tenth embodiment will be referred to as “scanning electron microscope SEMj”) will be described. FIG. 34 is a cross-sectional view showing the structure of the scanning electron microscope SEMj of the tenth embodiment.

As shown in FIG. 34, the scanning electron microscope SEMj of the tenth embodiment is compared with the scanning electron microscope SEMg of the seventh embodiment described above, and the position of the beam irradiation device 1f (that is, the position of the injection surface 12LS). ), And the measuring device 8g for measuring the positions of the stage 22 and the sample W (that is, the positions of the holding surface HS and the surface WSu) are separately provided. Hereinafter, for convenience of explanation, the measuring device 8g for measuring the position of the beam irradiation device 1f is referred to as a measuring device 8ga, and the measuring device 8g for measuring the positions of the stage 22 and the sample W is referred to as a measuring device 8gb. Distinguish. Other features of the scanning electron microscope SEMj may be the same as those of the scanning electron microscope SEMg.

The measuring device 8ga is the same as the measuring device 8g provided in the scanning electron microscope SEMg (see FIG. 20) of the seventh embodiment described above. That is, the measuring device 8ga is arranged at a fixed position with respect to the beam irradiating device 1f. However, the measuring device 8ga may be arranged at a position fixed with respect to the stage 22, or may be arranged at a position non-fixed with respect to the beam irradiation device 1f and the stage 22. Although the measuring device 8ga measures the position of the injection surface 12LS using the reference member BM, the position of the injection surface 12LS may be measured without using the reference member BM. The measuring device 8ga specifies the position of the injection surface 12LS in the first measurement coordinate space with respect to the measuring device 8ga.

The measuring device 8gb is the same as the measuring device 8g provided in the scanning electron microscope SEMh (see FIG. 32) of the eighth embodiment described above. That is, the measuring device 8 gb is arranged at a fixed position with respect to the stage 22. However, the measuring device 8gb may be arranged at a position fixed with respect to the beam irradiation device 1f, or may be arranged at a position non-fixed with respect to the beam irradiation device 1f and the stage 22. The measuring device 8gb measures the positions of the holding surface HS and the surface WSu using the reference member BM, but the positions of the holding surface HS and the surface WSu may be measured without using the reference member BM. The measuring device 8gb specifies the positions of the holding surface HS and the surface WSu in the second measurement coordinate space with respect to the measuring device 8gb.

The scanning electron microscope SEMj can perform the first control operation shown in FIG. 22 in the same manner as the scanning electron microscope SEMg described above. However, in the tenth embodiment, the measuring device 8ga specifies the position of the injection surface 12LS in the first measurement coordinate space with respect to the measuring device 8ga, while the measuring device 8gb uses the measuring device 8gb as a reference. The position of the holding surface HS in the second measurement coordinate space (that is, the second measurement coordinate space different from the first measurement coordinate space) is specified. That is, the coordinate space in which the measuring device 8ga specifies the position of the injection surface 12LS and the coordinate space in which the measuring device 8gb specifies the position of the holding surface HS (furthermore, the position of the surface WSuv of the virtual sample Wv) are different. .. Therefore, the scanning electron microscope SEMj associates the first measurement coordinate space based on the measuring device 8ga with the second measurement coordinate space based on the measuring device 8gb before performing step S17 in FIG. 22.

For example, in the scanning electron microscope SEMj, as shown in FIG. 35 (a), the first measurement coordinate space and the first measurement coordinate space are used by using the reference member BMC whose positional relationship between the two reference surfaces BSc1 and BSc2 is known to the control device 4. 2 It may be associated with the measurement coordinate space. Specifically, the measuring device 8ga measures the position of the reference plane BSc1 in the first measurement coordinate space. Further, the measuring device 8gb measures the position of the reference plane BSc2 in the second measurement coordinate space. After that, the control device 4 associates the first and second measurement coordinate spaces with each other based on the known positional relationship between the reference planes BSc1 and BSc2 and the measurement result of the positions of the reference planes BSc1 and BSc2. As a result, the control device 4 can associate the position of the injection surface 12LS in the first measurement coordinate space with the position of the holding surface HS in the second measurement coordinate space. That is, the control device 4 can specify the positional relationship between the injection surface 12LS and the holding surface HS (that is, the positional relationship between the injection surface 12LS and the surface WSuv) within the common measurement coordinate space. Therefore, the control device 4 can specify the distance D'between the injection surface 12LS and the surface WSuv and the parallelism between the injection surface 12LS and the surface WSuv. Therefore, after associating the first and second measurement coordinate spaces, the control device 4 sets the interval D'to the desired interval D_stage in step S17 of FIG. 22 and the surface WSuv is parallel to the injection surface 12LS. As such, at least one position of the beam irradiation device 1f and the stage 22 can be controlled.

Alternatively, as shown in FIG. 35 (b), the scanning electron microscope SEMj uses two reference members BMc3 and BMc4 having two reference planes BSc3 and BSc4 whose positional relationship is known to the control device 4, respectively. The first and second measurement coordinate spaces may be associated. Specifically, the measuring device 8ga measures the position of the reference surface BSc3 in the first measurement coordinate space, and the measuring device 8gb measures the position of the reference surface BSc4 in the second measurement coordinate space. After that, the control device 4 associates the first and second measurement coordinate spaces with each other based on the known positional relationship between the reference planes BSc3 and BSc4 and the measurement result of the positions of the reference planes BSc3 and BSc4.

Alternatively, as shown in FIG. 35C, depending on the positional relationship between the measuring devices 8ga and 8gb, the measuring devices 8ga and 8gb can measure the position of the same reference surface BMc5 of the same reference member BMc5 (for example, The same reference plane BMc5 can be irradiated with the measurement light ML). In this case, the control device 4 determines the first and second measurement coordinate spaces based on the measurement result of the position of the reference surface BSc5 by the measuring device 8ga and the measurement result of the position of the reference surface BSc5 by the measuring device 8gb. It may be associated.

Further, the scanning electron microscope SEMj can perform the second control operation shown in FIG. 29 in the same manner as the scanning electron microscope SEMg described above. However, in the tenth embodiment, the scanning electron microscope SEMj causes the measuring device 8gb to measure the position of the surface WSu in step S22 of FIG. 29. Further, when the measuring device 8ga is arranged at a non-fixed position with respect to the beam irradiating device 1f, the scanning electron microscope SEMj has an injection surface 12LS on the measuring device 8ga before performing step S23 in FIG. To measure the position of. Further, the scanning electron microscope SEMj associates the first and second measurement coordinate spaces before performing step S23 in FIG. 29. After that, in step S23 of FIG. 29, the scanning electron microscope SEMj has an interval D of the desired interval D_taget based on the measured position of the injection surface 12LS and the position of the surface WSu, and the surface WSu with respect to the injection surface 12LS. The positions of at least one of the beam irradiation device 1 and the stage 22 are controlled so that they are parallel to each other. Note that the method of associating the first and second measurement coordinate spaces in the second control operation may be the same as the method of associating the first and second measurement coordinate spaces in the first control operation. Omit.

As described above, the scanning electron microscope SEMj of the tenth embodiment enjoys the same effect as the above-mentioned scanning electron microscope SEMg, although the number of measuring devices 8g included in the scanning electron microscope SEMj increases. can do.

(11) Scanning electron microscope SEMk of the eleventh embodiment
Subsequently, the scanning electron microscope SEM of the eleventh embodiment (hereinafter, the scanning electron microscope SEM of the eleventh embodiment will be referred to as “scanning electron microscope SEMk”) will be described. In the description of the seventh embodiment described above, the scanning electron microscope SEMg irradiates the sample W with the electron beam EB while moving the stage 22 along the XY plane before starting the measurement of the state of the sample W. The second control operation is performed. On the other hand, the scanning electron microscope SEMk of the eleventh embodiment irradiates the sample W with the electron beam EB while moving the stage 22 along the XY plane, and measures the state of the sample W at least a part of the period. It differs from the scanning electron microscope SEMg described above in that the second control operation is performed in the above. That is, the scanning electron microscope SEMk performs the second control operation in parallel with the operation of irradiating the sample W with the electron beam EB while moving the stage 22 along the XY plane and measuring the state of the sample W. Therefore, it is different from the scanning electron microscope SEMg described above. Therefore, in the following, the second control operation in the eleventh embodiment will be described with reference to FIG. 36. FIG. 36 is a flowchart showing the flow of the second control operation in the eleventh embodiment.

As shown in FIG. 36, the stage 22 holds the sample W (step S21). After that, the scanning electron microscope SEMk starts irradiating the sample W with the electron beam EB. That is, the scanning electron microscope SEMk starts acquiring information about the sample W. Therefore, the scanning electron microscope SEMk irradiates the sample W with the electron beam EB while moving the stage 22 along the XY plane (that is, moving the sample W along the XY plane).

During the period in which the scanning electron microscope SEMk irradiates the sample W with the electron beam EB and measures the state of the sample W, the measuring device 8 g is a part of the surface WSu of the sample W held by the stage 22. The position (that is, the posture or shape) of a certain measurement target surface DS is measured (step S32). The measurement target surface DS corresponds to a local region on the surface WSu including an irradiation region to which the electron beam EB is irradiated. Since the electron beam EB irradiates the sample W via the vacuum region VSP, the measurement target surface DS corresponds to a local region on the surface WSu including a region facing or covering the vacuum region VSP.

In order to measure the position of the measurement target surface DS, the distance sensor 81g irradiates the measurement target surface DS with the measurement light ML and detects the reflected light of the measurement light ML from the measurement target surface DS. Therefore, the distance sensor 81g is arranged at a position where the measurement light ML can be irradiated to the measurement target surface DS. However, since the measurement target surface DS is a local region on the surface WSu, when the distance sensor 81g is arranged at a position where the measurement light ML can be irradiated to the measurement target surface DS, a plurality of distance sensors 81g There is a possibility that the measurement light ML is applied only to a local region of the surface WSu. That is, there is a possibility that the plurality of distance sensors 81g cannot irradiate the plurality of discrete regions of the holding surface HS of the stage 22 holding the sample W with the measurement light ML. As a result, the control device 4 may not be able to specify the position of the holding surface HS of the stage 22 as a whole, which is large enough to include the measurement target surface DS from the measurement results of each distance sensor 81g. That is, the scanning electron microscope SEMj may not be able to properly perform the first control operation. Therefore, as shown in FIG. 37, the scanning electron microscope SEMj has a plurality of discrete regions of the holding surface HS (further, if necessary, a plurality of discrete regions of the surface WSu) as the measuring device 8 g. A measuring device 8g-1 including a plurality of distance sensors 81g-1 arranged so as to irradiate the measurement light ML, and a local region (for example, the measurement target region DS) of the surface WSu. A measuring device 8g-2 including a plurality of distance sensors 81g-2 arranged so as to irradiate the measuring light ML may be separately provided. That is, the scanning electron microscope SEMk is a measuring device 8g-1 for measuring the position of a relatively wide surface (for example, the entire holding surface HS wider than the measurement target surface DS or the entire surface WSu) as the measuring device 8g. And a measuring device 8g-2 for measuring the position of a relatively narrow surface (for example, the holding surface HS and the measurement target surface DS narrower than the surface WSu) may be separately provided. In this case, since the measurement target region DS is located on the optical axis AX of the beam optical system 11, the measurement device 8g-2 is configured as compared with the plurality of distance sensors 81g-1 constituting the measurement device 8g-1. The plurality of distance sensors 81g-2 are arranged closer to the optical axis AX (that is, inside the optical axis AX in the radial direction). However, if both the position of the holding surface HS as a whole and the position of the measurement target surface DS can be appropriately measured using the same measuring device 8g, the scanning electron microscope SEMk can be used with the measuring devices 8g-1 and 8g. -2 does not have to be provided separately.

The measurement result of the distance sensor 81g-2 is output to the control device 4. The control device 4 specifies the distance from each distance sensor 81g-2 to the measurement target surface DS based on the measurement result of each distance sensor 81g-2. As a result, the control device 4 can specify the position of the measurement target surface DS (that is, the position of each part of the measurement target surface DS in the measurement coordinate space). In other words, the control device 4 can specify an equation indicating the measurement target surface DS in the measurement coordinate space.

After that, as shown in FIG. 36, in the control device 4, the distance D_DS between the measurement target surface DS and the injection surface 12LS becomes the desired distance D_stage, and the measurement target surface DS becomes parallel to the injection surface 12LS. As described above, the positional relationship between the beam irradiation device 1f and the stage 22 is controlled (step S33). Specifically, the control device 4 is in the measurement coordinate space from the position of the injection surface 12LS specified in the first control operation and the position of the measurement target surface DS specified in step S32, as in step S23 of FIG. The positional relationship between the injection surface 12LS and the measurement target surface DS can be specified. That is, the control device 4 can specify the distance D_DS between the measurement target surface DS and the injection surface 12LS and the parallelism between the injection surface 12LS and the measurement target surface DS. Therefore, when the interval D_DS is not the desired interval D_taget, the control device 4 controls at least one of the stage drive system 23 and the position adjustment system 14 so that the interval D_DS becomes the desired interval D_target, and the beam irradiation device 1f and the control device 4. The positional relationship with the stage 22 is controlled. Further, when the injection surface 12LS and the measurement target surface DS are not parallel, the control device 4 determines at least the stage drive system 23 and the position adjustment system 14 so that the injection surface 12LS and the measurement target surface DS are parallel. One is controlled to control the positional relationship between the beam irradiation device 1f and the stage 22.

The operations from step S32 to step S33 described above are repeated as necessary. For example, in the example shown in FIG. 36, the operations from step S32 to step S33 are repeated until the scanning electron microscope SEMk finishes acquiring information about the sample W (step S34). Here, when the scanning electron microscope SEMk acquires information about the sample W, the stage 22 moves along the XY plane. When the stage 22 moves along the XY plane, the irradiation region of the electron beam EB moves relative to the surface WSu in the direction along the XY plane (that is, the direction along the surface WSu of the sample W). Is as described above. Therefore, in accordance with the movement of the stage 22 along the XY plane, the measurement target surface DS, which is a local region including the irradiation region of the electron beam EB in the direction along the XY plane, is also substantially. It moves relative to the surface WSu. Therefore, the scanning electron microscope SEMk measures the position (that is, the posture) of the measurement target surface DS moving on the surface WSu in the measurement coordinate space in accordance with the movement of the stage 22 along the XY plane, and The operation of controlling the positional relationship between the beam irradiation device 1f and the stage 22 is repeated based on the measurement result of the position of the measurement target surface DS. As a result, for example, in the process of measuring the state of the sample W including the surface WSu including the three planes WSu1 to WSu3 intersecting each other as shown in FIGS. 38 (a) to 38 (c), the measurement target surface DS During the period of being a local region on the plane WSu1, the control device 4 desires a distance D_DS between the plane WSu1 on which the measurement target surface DS exists and the injection surface 12LS, as shown in FIG. 38 (a). The positional relationship between the beam irradiation device 1f and the stage 22 is controlled so that the interval D_taget is set and the plane WSu1 is parallel to the injection surface 12LS. During the period when the measurement target surface DS is a local region on the plane WSu2, the control device 4 is between the plane WSu2 where the measurement target surface DS exists and the injection surface 12LS, as shown in FIG. 38 (b). The positional relationship between the beam irradiation device 1f and the stage 22 is controlled so that the interval D_DS is the desired interval D_taget and the plane WSu2 is parallel to the injection surface 12LS. During the period when the measurement target surface DS is a local region on the plane WSu3, the control device 4 is between the plane WSu3 where the measurement target surface DS exists and the injection surface 12LS, as shown in FIG. 38 (c). The positional relationship between the beam irradiation device 1f and the stage 22 is controlled so that the interval D_DS is the desired interval D_taget and the plane WSu1 is parallel to the injection surface 12LS.

As described above, the scanning electron microscope SEMk of the eleventh embodiment can enjoy the same effect as the effect that can be enjoyed by the scanning electron microscope SEMg described above. Further, in the eleventh embodiment, after the stage 22 holds the sample W (particularly after the scanning electron microscope SEMd starts measuring the state of the sample W), the interval D deviates from the desired interval D_taget for some reason. Even when the surface WSu is not parallel to the injection surface 12LS, the interval D becomes the desired interval D_target and the surface WSu is parallel to the injection surface 12LS. , The positional relationship between the beam irradiation device 1f and the stage 22 is controlled. That is, in parallel with the acquisition of information on the sample W by the scanning electron microscope SEMk, the beam irradiation device 1f so that the interval D becomes the desired interval D_taget and the surface WSu is parallel to the injection surface 12LS. The positional relationship between the and the stage 22 is controlled.

In the above description, the scanning electron microscope SEMk uses the measuring device 8g to position the measurement target surface DS moving on the surface WSu in the measurement coordinate space in parallel with the acquisition of information on the sample W. (That is, the posture or shape) is measured in real time. However, in the scanning electron microscope SEMk, the position of each portion of the surface WSu may be measured in advance using the measuring device 8g before starting the acquisition of the information regarding the sample W. Specifically, the scanning electron microscope SEMk divides the surface WSu into a plurality of divided regions using a measuring device 8 g before starting the acquisition of information on the sample W, and then positions each divided region (that is, that is). , Posture or shape) may be measured in advance. In this case, after starting the measurement of the state of the sample W, the scanning electron microscope SEMk does not measure the position (that is, the posture or shape) of the measurement target surface DS in real time by using the measuring device 8g, and the surface surface. A beam irradiator so that the interval D becomes the desired interval D_target and the surface WSu is parallel to the injection surface 12LS based on the preliminary measurement result of the position (that is, the posture or shape) of each part of the WSu. The positional relationship between 1f and the stage 22 may be controlled. Specifically, the scanning electron microscope SEMk is a measurement target of the surface WSu from the measurement result of the position of each part of the surface WSu (that is, information on the position of each part previously measured by the measuring device 8g). Information on the position of the portion where the surface DS is set may be acquired, and the positional relationship between the beam irradiation device 1 and the stage 22 may be controlled based on the information on the position of the acquired portion.

Further, in the above description, the measurement target surface DS is a local region on the surface WSu including an irradiation region to which the electron beam EB is irradiated (that is, on the surface WSu including a region facing or covering the vacuum region VSP. It is set in the local area of. However, the measurement target surface DS may be set to a local region on the surface WSu that does not include the irradiation region to which the electron beam EB is irradiated. The measurement target surface DS may be set to a local region on the surface WSu that does not include a region facing or covering the vacuum region VSP. In this case, the scanning electron microscope SEMk irradiates the first surface portion of the surface WSu of the sample W with the electron beam EB, and the second surface portion different from the first surface portion of the surface WSu of the sample W. The position of may be measured. After that, the scanning electron microscope SEMk is based on the measurement result of the position of the second surface portion measured in advance when irradiating the second surface portion of the surface WSu of the sample W with the electron beam EB. The positional relationship between the beam irradiation device 1f and the stage 22 so that the distance D between the second surface portion and the injection surface 121f is the desired distance D_target and the second surface portion is parallel to the injection surface 12LS. May be controlled.

(12) Scanning electron microscope SEMl of the twelfth embodiment
Subsequently, the scanning electron microscope SEM of the twelfth embodiment (hereinafter, the scanning electron microscope SEM of the twelfth embodiment is referred to as “scanning electron microscope SEMl”) will be described with reference to FIG. 39. FIG. 39 is a cross-sectional view showing the structure of the scanning electron microscope SEMl of the twelfth embodiment.

As shown in FIG. 39, the scanning electron microscope SEMl of the twelfth embodiment is different from the scanning electron microscope SEMa of the first embodiment described above in that it includes an optical microscope 17l. The other structure of the scanning electron microscope SEMl may be the same as the other structure of the scanning electron microscope SEMa described above.

The optical microscope 17l is a device capable of optically measuring the state of the sample W (for example, the state of at least a part of the surface WSu of the sample W). That is, the optical microscope 17l is an apparatus capable of optically measuring the state of the sample W and acquiring information on the sample W. In particular, the optical microscope 17l is different from the beam irradiation device 1 (particularly, the electron detector 117) that measures the state of the sample W in a vacuum environment in that the state of the sample W can be measured in an atmospheric pressure environment. different.

The optical microscope 17l measures the state of the sample W before the beam irradiation device 1 irradiates the sample W with the electron beam EB to measure the state of the sample W. That is, the scanning electron microscope SEMl measures the state of the sample W using the optical microscope 17l and then measures the state of the sample W using the beam irradiation device 1. Here, since the optical microscope 17l can measure the state of the sample W in an atmospheric pressure environment, the beam irradiating device 1 sets the vacuum region VSP during the period when the optical microscope 17l is measuring the state of the sample W. It does not have to be formed. On the other hand, the beam irradiation device 1 forms a vacuum region VSP and irradiates the sample W with the electron beam EB after the optical microscope 17l completes the measurement of the state of the sample W.

The stage 22 may move so that the sample W is located at a position where the beam irradiation device 1 can irradiate the electron beam EB while the beam irradiation device 1 irradiates the sample W with the electron beam EB. The stage 22 may be moved so that the sample W is located at a position where the optical microscope 17l can measure the state of the sample W while the electron microscope 17l measures the state of the sample W. The stage 22 may move between a position where the beam irradiation device 1 can irradiate the electron beam EB and a position where the optical microscope 17l can measure. FIG. 40 is a cross-sectional view showing a stage 22 in which the beam irradiation device 1 has moved so that the sample W is positioned at a position where the electron beam EB can be irradiated. FIG. 41 is a cross-sectional view showing a stage 22 in which the optical microscope 17l is moved so that the position sample W where the state of the sample W can be measured is located.

The beam irradiation device 1 is used for at least a part of the period during which the sample W is located at a position where the optical microscope 17l can measure the state of the sample W (hereinafter, for convenience of explanation, this period is referred to as an “optical measurement period”). May form a vacuum region VSP with the surface of the stage 22. That is, even during at least a part of the optical measurement period, the beam irradiation device 1 may continue to form the vacuum region VSP as during the period during which the beam irradiation device 1 irradiates the sample W with the electron beam EB. For example, as shown in FIG. 42, the beam irradiator 1 is located on the surface of the stage 22 different from the holding surface HS (typically outside the holding surface HS) during at least a portion of the optical measurement period. ) A vacuum region VSP may be formed between the outer peripheral surface OS and the peripheral surface OS. In this case, in a state where the sample W held on the holding surface HS faces the optical microscope 17l, the outer peripheral surface OS of the stage 22 can face the beam irradiation device 1 (particularly, the injection surface 12LS). Properties (eg, at least one of shape and size) may be set.

When the beam irradiation device 1 forms a vacuum region VSP with the outer peripheral surface OS, the height of the outer peripheral surface OS (that is, the position in the Z-axis direction) is the surface of the wafer W held by the holding surface HS. It may be the same as the height of WSu. In this case, it is possible to reduce the possibility that the vacuum region VSP is destroyed when the vacuum region VSP crosses the boundary between the outer peripheral surface OS and the surface WSu of the sample W as the stage 22 moves. That is, the stage 22 has a position where the optical microscope 17l shown in FIG. 42 can measure the sample W and the beam irradiation device 1 can form a vacuum region VSP between the outer peripheral surface OS and the beam shown in FIG. 43. The vacuum region VSP is destroyed at a position where the irradiation device 1 can form a vacuum region VSP with the sample W (that is, a position where the beam irradiation device 1 can irradiate the sample W with the electron beam EB). You can move while reducing the possibility. As a result, for example, as shown in FIG. 42, the stage 22 is XY from the state where the optical microscope 17l can measure the sample W and the beam irradiation device 1 can form a vacuum region VSP with the outer peripheral surface OS. When moving along a plane (for example, along the Y-axis direction in the examples shown in FIGS. 42 and 43), the beam irradiator 1 irradiates the sample W with the electron beam EB via the vacuum region VSP. Can be done. As a result, the throughput of the scanning electron microscope SEMl is improved as compared with the case where a vacuum region VSP needs to be newly formed as the stage 22 moves.

The scanning electron microscope SEMl may measure the state of the sample W using the beam irradiation device 1 based on the measurement result of the state of the sample W using the optical microscope 17l. For example, the scanning electron microscope SEMl may first measure the state of a desired region of the sample W using an optical microscope 17l. After that, the scanning electron microscope SEMl uses the beam irradiation device 1 to obtain the same desired region state (or desired region) of the sample W based on the measurement result of the desired region state of the sample W using the optical microscope 17l. May measure the state of different regions). In this case, a predetermined index object that can be used for measuring the state of the sample W using the beam irradiation device 1 may be formed in the desired region of the sample W. As an example of a predetermined index object, for example, a mark used for aligning the sample W and the beam irradiation device 1 (for example, at least one of a fiducial mark and an alignment mark) can be mentioned.

Alternatively, as described above, a fine uneven pattern is formed on the surface WSu of the sample W. For example, when the sample W is a semiconductor substrate, an example of a fine uneven pattern is a resist pattern that remains on the semiconductor substrate after the semiconductor substrate coated with the resist is exposed by the exposure apparatus and developed by the developing apparatus. Be done. In this case, for example, the scanning electron microscope SEMl may first measure the state of the uneven pattern formed in the desired region of the sample W by using the optical microscope 17l. After that, the scanning electron microscope SEMl uses the optical microscope 17l to measure the state of the desired region of the sample W (that is, the measurement result of the state of the uneven pattern formed in the desired region), and then the beam irradiation device 1 May be used to measure the state of the uneven pattern formed in the same desired region of the sample W. For example, the scanning electron microscope SEMl controls the characteristics of the electron beam EB so that the optimum electron beam EB for measuring the unevenness pattern is irradiated based on the measurement result of the optical microscope 17l, and then the beam irradiation device 1 May be used to measure the state of the uneven pattern formed in the same desired region of the sample W.

The scanning electron microscope SEMl of the twelfth embodiment can enjoy the same effect as the effect that the scanning electron microscope SEMa can enjoy. In addition, the scanning electron microscope SEMl of the twelfth embodiment more appropriately measures the state of the sample W using the electron beam EB as compared with the scanning electron microscope of the comparative example not provided with the optical microscope 17l. be able to.

In the above description, the scanning electron microscope SEMl measures the state of the sample W using the optical microscope 17l and then measures the state of the sample W using the beam irradiation device 1. However, in the scanning electron microscope SEMl, the measurement of the state of the sample W using the optical microscope 17l and the measurement of the state of the sample W using the beam irradiation device 1 may be performed in parallel. For example, the scanning electron microscope SEMl may simultaneously measure the state of the desired region of the sample W using the optical microscope 17l and the beam irradiation device 1. Alternatively, the scanning electron microscope SEMl measures the state of the first region of the sample W using the optical microscope 17l and the second region of the sample W using the beam irradiation device 1 (however, the second region is the first region). The measurement of the state (different from) may be performed in parallel.

Further, the scanning electron microscope SEMl may be provided with an arbitrary measuring device capable of measuring the state of the sample W in an atmospheric pressure environment in addition to or in place of the optical microscope 17l. An example of an arbitrary measuring device is a diffraction interferometer. The diffraction interferometer, for example, branches the light source light to generate measurement light and reference light, and irradiates the sample W with the measurement light to generate reflected light (or transmitted light or scattered light) and reference light. This is a measuring device that detects an interference pattern generated by interference with light and measures the state of sample W (for example, the surface shape of sample W). As another example of the arbitrary measuring device, a scatometer can be mentioned. The scatometer is a measuring device that irradiates the sample W with measurement light and receives scattered light (diffracted light or the like) from the sample W to measure the state of the sample W.

Further, in the above description of the scanning electron microscope SEMl, the scanning electron microscope SEMa of the first embodiment is provided with an optical microscope 17l. However, even if each of the scanning electron microscope SEMa of the second embodiment to the scanning electron microscope SEMk of the eleventh embodiment (furthermore, the scanning electron microscope SEMm of the thirteenth embodiment described later) includes an optical microscope 17l. Good.

(13) Scanning electron microscope SEMm of the thirteenth embodiment
Subsequently, with reference to FIG. 44, the scanning electron microscope SEM of the thirteenth embodiment (hereinafter, the scanning electron microscope SEM of the fourteenth embodiment will be referred to as “scanning electron microscope SEMm”) will be described. FIG. 44 is a cross-sectional view showing the structure of the scanning electron microscope SEMm of the thirteenth embodiment.

As shown in FIG. 44, the scanning electron microscope SEMm of the thirteenth embodiment includes a chamber 181 m and an air conditioner 182 m as compared with the scanning electron microscope SEMa of the first embodiment described above. Is different. The other structure of the scanning electron microscope SEMm may be the same as the other structure of the scanning electron microscope SEMa described above.

The chamber 181 m accommodates at least the beam irradiation device 1, the stage device 2, and the support frame 3. However, the chamber 181m does not have to accommodate at least a part of the beam irradiation device 1, the stage device 2, and the support frame 3. The chamber 181 m may accommodate other components of the scanning electron microscope SEMm (eg, at least a portion of the position measuring device 15, the control device 4, the pump system 5, the gas supply device 6 and the exhaust device 7). Good.

The space outside the chamber 181 m is, for example, an atmospheric pressure space. The space inside the chamber 181 m (that is, the space that accommodates at least the beam irradiation device 1, the stage device 2, and the support frame 3) is also, for example, an atmospheric pressure space. In this case, at least the beam irradiation device 1, the stage device 2, and the support frame 3 are arranged in the atmospheric pressure space. However, as described above, the beam irradiator 1 forms a local vacuum region VSP in the atmospheric pressure space inside the chamber 181 m.

The air conditioner 182 m can supply a gas (for example, at least one of the above-mentioned inert gas and clean dry air) to the space inside the chamber 181 m. The air conditioner 182 m can recover gas from the space inside the chamber 181 m. The air conditioner 182 m recovers the gas from the space inside the chamber 181 m, so that the cleanliness of the space inside the chamber 181 m is kept good. At this time, the air conditioner 182m can control at least one of the temperature and humidity of the space inside the chamber 181m by controlling at least one of the temperature and humidity of the gas supplied to the space inside the chamber 181m.

The scanning electron microscope SEMm of the thirteenth embodiment can enjoy the same effect as the effect that the scanning electron microscope SEMa can enjoy.

In the above description of the scanning electron microscope SEMm, the scanning electron microscope SEMa of the first embodiment is provided with a chamber 181 m and an air conditioner 182 m. However, each of the scanning electron microscope SEMa of the second embodiment to the scanning electron microscope SEMl of the twelfth embodiment may include a chamber 181 m and an air conditioner 182 m.

(14) Scanning electron microscope SEMn of the 14th embodiment
Subsequently, the scanning electron microscope SEM of the 14th embodiment (hereinafter, the scanning electron microscope SEM of the 14th embodiment will be referred to as “scanning electron microscope SEMn”) will be described. The scanning electron microscope SEMn of the 14th embodiment is different from the scanning electron microscope SEMa of the first embodiment described above in that it includes a pump system 5n instead of the pump system 5. The other structure of the scanning electron microscope SEMn may be the same as the other structure of the scanning electron microscope SEMa described above. Therefore, in the following, the pump system 5n of the 14th embodiment will be described with reference to FIG. 45. FIG. 45 is a schematic view showing the structure of the pump system 5n of the 14th embodiment.

As shown in FIG. 45, the pump system 5n is different from the pump system 5 in that it includes

vacuum pumps

51n and 52n instead of the

vacuum pumps

51 and 52. The vacuum pump 51n is different from the vacuum pump 51 in that a part of the vacuum pump 51n is shared as a part of the vacuum pump 52n, and a part of the vacuum pump 51 does not have to be shared as the vacuum pump 52. The vacuum pump 52n is different from the vacuum pump 52 in that a part of the vacuum pump 52n is shared as a part of the vacuum pump 51n, and a part of the vacuum pump 52 does not have to be shared as the vacuum pump 51. The other structure of the pump system 5n may be the same as the other structure of the pump system 5 described above.

As an example, as shown in FIG. 45, the vacuum pump 51n includes a high vacuum pump 511n used as a main pump and an auxiliary pump (specifically, a high vacuum pump 511n), similarly to the vacuum pump 51 described above. It is equipped with a low vacuum pump 512n used as a back pump). As an example of the high vacuum pump 511n, for example, at least one of a turbo molecular pump, a diffusion pump, a cryopump and a sputter ion pump can be mentioned. An example of the low vacuum pump 512n is a dry pump. The vacuum pump 51n exhausts the beam passing space SPb1 in the beam optical system 11 and the beam passing space SPb2 in the differential exhaust system 12 via the pipe 117. A pressure gauge 591n may be arranged in the pipe 117, or a pressure gauge 592n between the beam passage space SPb1 and the beam passage space SPb2 (that is, between the beam optical system 11 and the differential exhaust system 12). May be arranged. Further, a valve 592n may be arranged between the beam passing space SPb1 and the pressure gauge 592n and the beam passing space SPb2. The gas supply device 6 is connected to the beam passage space SPb2 via the opening 126 and the pipe 127 (however, not shown in FIG. 45), the pipe 1291, and the valve 1281, and the opening 126 and the pipe 127. (However, it is not shown in FIG. 45) and the exhaust device 7 is connected via the pipe 1292 and the valve 1282, which is the same as that of the first embodiment. On the other hand, the vacuum pump 52n includes a low vacuum pump 512n and a low vacuum pump 522n (for example, a dry pump). That is, the vacuum pump 51n and the vacuum pump 52 share a low vacuum pump 512n. The low vacuum pump 512n exhausts the air through the exhaust passage EP1 (specifically, the first-stage differential exhaust). The low vacuum pump 522n exhausts air through the exhaust passage EP2 (specifically, second-stage differential exhaust gas). In the example shown in FIG. 45, the pump system 5n can function as a low vacuum pump 512n instead of the

low vacuum pumps

512n and 522n, and can also function as a low vacuum pump 522n. A vacuum pump may be provided. That is, in the pump system 5n, the

low vacuum pumps

512n and 522n may be combined with one low vacuum pump.

The scanning electron microscope SEMn shown in FIG. 45 may operate as follows, for example. For example, when the scanning electron microscope SEMn is stopped, the control device 4 may set the valves 593n in the open state and the

valves

1281 and 1282 in the closed state. When the scanning electron microscope SEMn starts operation, first, the

low vacuum pumps

512n and 522n may start exhausting. After that, when the measured value of the pressure gauge 591n becomes equal to or less than the first predetermined value (for example, 200 pascals) due to the exhaust of the beam passage space SPb1 by the low vacuum pump 512n, the high vacuum pump 511n starts exhausting. May be good. When the measured value of the pressure gauge 591n becomes equal to or less than the second predetermined value (for example, 0.1 Pascal) due to the exhaust of the beam passing space SPb1 by the high vacuum pump 511n, the scanning electron microscope SEMn is the electron beam EB. Irradiation may be started.

Further, when gas is supplied by the gas supply device 6 and / or exhaust is performed by the exhaust device 7, the control device 4 sets the valves 593n in the closed state and the

valves

1281 and 1282 in the open state. You may. In the situation where the valve 593n is set to the open state, the control device 4 should, in principle (that is, except for some exceptional situations), set the

valves

1281 and 1282 to the open state. You may limit it. That is, in principle, the control device 4 may limit the setting of all the

valves

593n, 1281 and 1282 to the open state at the same time. In this case, the control device 4 may control the

valves

1281 and 1291 so that the measured value of the pressure gauge 592n is equal to or less than the third predetermined value (for example, 100 pascals). However, in a situation where the measured value of the pressure gauge 592n is equal to or less than the third predetermined value but higher than the second predetermined value, the collector of the secondary electron detector (that is, the secondary electrons, which is a specific example of the electron detector 117). Since the voltage application portion for collecting the secondary electrons is discharged, it may be difficult for the secondary electron detector to detect the secondary electrons. Therefore, in a situation where the measured value of the pressure gauge 592n is equal to or less than the third predetermined value, the backscattered electron detector, which is a specific example of the electron detector 117, may detect the backscattered electrons. When the gas supply by the gas supply device 6 and / or the exhaust by the exhaust device 7 is terminated, the control device 4 sets the valves 593n in the open state and the

valves

1281 and 1282 in the closed state. May be good. As a result, the measured value of the pressure gauge 592n returns to the second predetermined value or less.

When the scanning electron microscope SEMn starts and ends the operation, the

valves

1281 and 1282 are set to the closed state, then the valves 593n are set to the open state, and then the high vacuum pump 511n is stopped, and then the high vacuum pump 511n is stopped. The low vacuum pump 522n is stopped, and then the low vacuum pump 512n is stopped. It should be noted that the stoppage of the operation of the low vacuum pump 512n may be restricted until the operation of the high vacuum pump 511n is stopped (for example, the turbine blades are stopped). When the measured value of the pressure gauge 591n becomes an abnormal value (for example, the above-mentioned first predetermined value (for example, 200 pascals) or more), the scanning electron microscope SEMn ends its operation. A similar operation (that is, an operation of stopping each pump) may be performed. When the state in which the measured value of the pressure gauge 591n becomes an abnormal value continues for a predetermined time (for example, 5 minutes) or more, the operation is the same as when the scanning electron microscope SEMn ends the operation (that is, each pump is operated. The operation to stop) may be performed.

The scanning electron microscope SEMn of the 14th embodiment can enjoy the same effect as the effect that the scanning electron microscope SEMa can enjoy. Further, in the 14th embodiment, the number of pumps used in the pump system 5n is smaller than that in the 1st embodiment.

In the above description of the scanning electron microscope SEMn, the scanning electron microscope SEMa of the first embodiment is provided with a pump system 5n. However, each of the scanning electron microscope SEMa of the second embodiment to the scanning electron microscope SEMm of the thirteenth embodiment may include a pump system 5n.

(15) Scanning electron microscope SEMo of the fifteenth embodiment
Subsequently, the scanning electron microscope SEM of the fifteenth embodiment (hereinafter, the scanning electron microscope SEM of the fifteenth embodiment will be referred to as “scanning electron microscope SEMO”) will be described. The scanning electron microscope SEMO of the fifteenth embodiment is different from the scanning electron microscope SEMa of the first embodiment described above in that it includes a beam irradiating device 1o instead of the beam irradiating device 1. .. Other features of the scanning electron microscope SEMo may be the same as those of the scanning electron microscope SEMa described above. Therefore, in the following, the structure of the beam irradiation device 1o will be described with reference to FIG. 46. FIG. 46 is a cross-sectional view showing the structure of the beam irradiation device 1o included in the scanning electron microscope SEM of the fifteenth embodiment.

As shown in FIG. 46, the beam irradiation device 1o is different from the beam irradiation device 1 in that the electron detector 117 may be arranged in the pipe 127 connected to the opening 126. Other features of the beam irradiating device 1o may be the same as those of the beam irradiating device 1 described above.

The electron detector 117 arranged in the pipe 127 may be a reflected electron detector that detects reflected electrons from the sample W. The electron detector 117 arranged in the pipe 127 may be a secondary electron detector that detects electrons generated by irradiation of the sample W with the electron beam EB. The electron detector 117 arranged in the pipe 127 may be a semiconductor type electron detector or an ET (Everhard-Tornley) detector. The same type of electron detector 117 may be arranged in each of the plurality of pipes 127 connected to the plurality of openings 126, or different types of electron detectors 117 may be arranged.

An energy dispersive X-ray analysis (EDX, EDS: Energy dispersive X-ray spectrum) analyzer may be arranged in the pipe 127 connected to the opening 126. In energy dispersive X-ray analysis, characteristic X-rays (fluorescent X-rays) generated by irradiation of sample W with electron beam EB are introduced into, for example, a semiconductor detector, and the energy and number of electron-hole pairs generated are used. The elements constituting the sample W are analyzed. Particle-induced X-ray Emission (PIXE) may be performed to analyze X-rays generated by irradiating the sample W with a charged particle beam instead of the electron beam EB.

A detector for EDX may be arranged in each of the plurality of pipes 127 connected to the plurality of openings 126. An electron detector and a detector for EDX may be arranged in each of the plurality of pipes 127 connected to the plurality of openings 126.

The scanning electron microscope SEMo of the fifteenth embodiment can enjoy the same effect as the effect that the scanning electron microscope SEMa can enjoy.

In the above description of the scanning electron microscope SEMo, the scanning electron microscope SEMa of the first embodiment is provided with an electron detector 117 arranged in the pipe 127. However, each of the scanning electron microscope SEMa of the second embodiment to the scanning electron microscope SEMn of the fourteenth embodiment may include an electron detector 117 arranged in the pipe 127.

(16) A modified example common to the scanning electron microscope SEMa of the first embodiment to the scanning electron microscope SEMn of the fourteenth embodiment.
(16-1) First Modified Example In the above description, the sample W has a size large enough that the vacuum region VSP can cover only a part of the surface WSu of the sample W. On the other hand, in the first modification, as shown in FIG. 47, which is a cross-sectional view showing how the stage 22 holds the sample W in the first modification, in the sample W, the vacuum region VSP is the surface WSu of the sample W. It may have a size small enough to cover the whole. Alternatively, the sample W may have a size small enough that the beam passing space SPb3 included in the vacuum region VSP can cover the entire surface WSu of the sample W. In this case, as shown in FIG. 47, the vacuum region VSP formed by the differential exhaust system 12 may cover the surface WSu of the sample W and / or face (ie, touch) the surface WSu of the sample W. In addition, it covers at least a portion of the surface of the stage 22 (eg, the outer peripheral OS of the surface of the stage 22 that is different from the holding surface HS) and / or at least the surface of the stage 22 (eg, the outer peripheral OS). It may face a part. The outer peripheral surface OS typically includes a surface located around the holding surface HS. For convenience of explanation, FIG. 47 shows an example in which the scanning electron microscope SEMa of the first embodiment irradiates the small-sized sample W described in the first modification with the electron beam EB. Each of the scanning electron microscope SEMb of the second embodiment to the scanning electron microscope SEMo of the fifteenth embodiment may also irradiate the small-sized sample W described in the first modification with the electron beam EB. Needless to say.

In the first modification, in the scanning electron microscope SEMa of the first embodiment to the scanning electron microscope SEMo of the fifteenth embodiment, the distance D between the injection surface 12LS of the beam emitting device 1 and the surface WSu of the sample W is set. Instead of the desired interval D_taget, the interval adjusting system 14 (or position) so that the interval Do1 between the holding surface HS or the outer peripheral surface OS on the surface of the injection surface 12LS and the stage 22 becomes the desired interval D_taget. At least one of the adjustment system 14 g) and the stage drive system 23 may be controlled.

Further, at least one of the scanning electron microscope SEMg of the seventh embodiment to the scanning electron microscope SEMk of the eleventh embodiment that performs the position control operation is formed by the injection surface 12LS of the beam emitting device 1f and the surface WSu of the sample W. Instead of performing the position control operation so that the interval D between them becomes the desired interval D_taget and / or the injection surface 12LS and the surface WSu are parallel to each other, the injection surface 12LS and the holding surface HS or the outer peripheral surface OS The position control operation may be performed so that the interval Do1 between the intervals is the desired interval D_taget and / or the injection surface 12LS and the holding surface HS or the outer peripheral surface OS are parallel to each other. For example, at least one of the scanning electron microscopes SEMg to SEMk estimates the position of the injection surface 12LS in the first control operation (steps S11 to S13 in FIG. 22), and the holding surface HS or the outer peripheral surface OS of the stage 22. The position is measured (process corresponding to step S15 in FIG. 22), and the beam irradiation device 1 and the stage are set so that the injection surface 12LS and the holding surface HS or the outer peripheral surface OS are parallel and the interval Do1 is the desired interval D_taget. The positional relationship with the 22 may be controlled (process corresponding to step S17 in FIG. 22). As a result, in at least one of the scanning electron microscopes SEMg to SEMk, the injection surface 12LS and the holding surface HS or the outer peripheral surface OS are parallel to each other and the interval Do1 is the desired interval D_taget even if the second control operation is not necessarily performed. In this state, the sample W can be irradiated with the electron beam EB. However, also in the first modification, at least one of the scanning electron microscopes SEMg to SEMk may perform the second control operation. That is, at least one of the scanning electron microscopes SEMg to SEMk measures the position of the holding surface HS or the outer peripheral surface OS of the stage 22 after the stage 22 holds the sample W (step S21 in FIG. 29) (FIG. 29). The process corresponding to step S22), the distance Do1 between the holding surface HS or the outer peripheral surface OS and the injection surface 12LS becomes the desired distance D_target, and the holding surface HS or the outer peripheral surface OS is parallel to the injection surface 12LS. Therefore, the positional relationship between the beam irradiation device 1f and the stage 22 may be controlled (process corresponding to step S23 in FIG. 29).

(15-2) Second Modified Example In the first modified example, the holding surface HS of the stage 22 and the outer peripheral surface OS of the stage 22 were located at the same height. On the other hand, in the second modification, as shown in FIG. 48, which is a cross-sectional view showing how the stage 22 holds the sample W in the second modification, the holding surface HS and the outer peripheral surface OS have different heights (that is, the outer peripheral surface OS). , Different positions in the Z-axis direction). FIG. 48 shows an example in which the holding surface HS is located at a position lower than the outer peripheral surface OS, but the holding surface HS may be located at a position higher than the outer peripheral surface OS. When the holding surface HS is located at a position lower than the outer peripheral surface OS, the stage 22 is substantially a storage space in which the sample W is housed (that is, a space recessed so as to house the sample W). Can be said to have been formed. Further, FIG. 48 shows an example in which the outer peripheral surface OS is located at a position higher than the surface WSu of the sample W, but the outer peripheral surface OS may be located at a position lower than the surface WSu, or the outer peripheral surface. The OS may be located at the same height as the surface WSu. In FIG. 48, for convenience of explanation, the scanning electron microscope SEMa of the first embodiment has an electron beam on a sample W held on a holding surface HS having a height different from that of the outer peripheral surface OS described in the second modification. Although an example of irradiating EB is shown, each of the scanning electron microscope SEMb of the second embodiment to the scanning electron microscope SEM of the fifteenth embodiment is higher than the outer peripheral surface OS described in the second modification. Needless to say, the electron beam EB may be applied to the sample W held on the holding surface HS having a different shape.

In the second modification, as in the first modification, the sample W may have a size small enough that the vacuum region VSP can cover the entire surface WSu of the sample W. In this case, as in the first modification, the vacuum region VSP formed by the differential exhaust system 12 covers the surface WSu of the sample W and / or faces the surface WSu of the sample W, and in addition, the stage 22 It may cover at least a portion of the surface (eg, the outer peripheral OS) and / or may face at least a portion of the surface of the stage 22 (eg, the outer peripheral OS). Alternatively, the sample W may have a size large enough that the vacuum region VSP can cover only a part of the surface WSu of the sample W. In this case, the vacuum region VSP formed by the differential exhaust system 12 covers a part of the surface WSu of the sample W and / or faces a part of the surface WSu of the sample W while facing the surface of the stage 22 (eg, the surface WSu). It does not have to cover at least a part of the outer peripheral surface OS) and / or may not face at least a part of the surface of the stage 22 (for example, the outer peripheral surface OS).

Also in the second modification, similarly to the first modification, at least one of the scanning electron microscope SEMa of the first embodiment to the scanning electron microscope SEMo of the fifteenth embodiment has an injection surface 12LS and a surface WSu. The interval adjusting system 14 (or the position adjusting system 14 g) and the interval adjusting system 14 (or the position adjusting system 14 g) so that the interval Do1 between the injection surface 12LS and the outer peripheral surface OS becomes the desired interval D_target instead of the desired interval D_target. At least one of the stage drive systems 23 may be controlled. Further, in at least one of the scanning electron microscope SEMk of the seventh embodiment to the scanning electron microscope SEMk of the eleventh embodiment in which the position control operation is performed, the distance D between the injection surface 12LS and the surface WSu is a desired distance D_target. In addition to or instead of performing a position control operation so that the injection surface 12LS and the surface WSu are parallel to each other, the interval Do1 between the injection surface 12LS and the outer peripheral surface OS is a desired interval. The position control operation may be performed so as to be D_target and / or so that the injection surface 12LS and the outer peripheral surface OS are parallel to each other.

The scanning electron microscope SEMl of the twelfth embodiment provided with the above-mentioned optical microscope 17l is provided with an electron beam EB on a sample W held on a holding surface HS having a height different from that of the outer peripheral surface OS described in the second modification. Even in the case of irradiation, as described in the twelfth embodiment, at least a part of the period (that is, the optical measurement period) in which the sample W is located at a position where the state of the sample W can be measured by the optical microscope 17l. The beam irradiation device 1 may form a vacuum region VSP with the surface of the stage 22 (for example, the outer peripheral surface OS). Further, after the optical measurement period is completed, the stage 22 is XY from a state in which the optical microscope 17l can measure the sample W and the beam irradiation device 1 can form a vacuum region VSP with the outer peripheral surface OS. It may move along a plane. As a result, the beam irradiation device 1 can irradiate the sample W with the electron beam EB via the vacuum region VSP.

Further, the holding surface HS may hold a holder for holding the sample W instead of directly holding the sample W. That is, the holding surface HS may indirectly hold the sample W via a holder that holds the sample W. For example, in FIG. 49, the sample W is held by the holder HW, and the holder HW is held in a state where the holder HW is housed in a step (in other words, a storage space or a pocket) formed by the holding surface HS and the outer peripheral surface OS. It is sectional drawing which shows the holding surface HS. Even in this case, the scanning electron microscope SEMl of the twelfth embodiment including the above-mentioned optical microscope 17l is a period in which the sample W is located at a position where the optical microscope 17l can measure the state of the sample W (that is, optical). A vacuum region VSP may be formed between the surface of the stage 22 (for example, the outer peripheral surface OS) at least a part of the measurement period). For example, FIG. 49 shows an example in which the beam irradiation device 1 forms a vacuum region VSP with the outer peripheral surface OS of the stage 22 during at least a part of the optical measurement period. Further, as shown in FIG. 49, the stage 22 is along the XY plane from the state where the optical microscope 17l can measure the sample W and the beam irradiation device 1 can form the vacuum region VSP with the outer peripheral surface OS. When moving (for example, along the Y-axis direction in the examples shown in FIGS. 49 and 50), the beam irradiator 1 has a vacuum region VSP formed between the holder HW and the holder HW as shown in FIG. The electron beam EB can be applied to the sample W via the above. The height of the outer peripheral surface OS (that is, the position in the Z-axis direction) may be the same as the height of the surface HWSu of the holder HW. In this case, it is possible to reduce the possibility that the vacuum region VSP is destroyed when the vacuum region VSP crosses the boundary between the outer peripheral surface OS and the surface HWSu of the holder HSu as the stage 22 moves. Therefore, the throughput of the scanning electron microscope SEMl is improved.

(15-3) Third Modified Example In the third modified example, the sample W is formed by the cover member 25 as shown in FIG. 51, which is a cross-sectional view showing how the stage 22 holds the sample W in the third modified example. It may be covered. That is, the electron beam EB may irradiate the sample W with the cover member 25 arranged between the sample W and the beam irradiating device 1 (particularly, the injection surface 12LS). At this time, a through hole may be formed in the cover member 25, and the electron beam EB may irradiate the sample W through the through hole of the cover member 25. The cover member 25 may be arranged above the sample W so as to be in contact with the surface WSu of the sample W or to secure a gap between the cover member 25 and the surface WSu. In this case, the differential exhaust system 12 may form a vacuum region VSP that covers at least a part of the surface 25s of the cover member 25 instead of the vacuum region VSP that covers at least a part of the surface WSu of the sample W. The differential exhaust system 12 may form a vacuum region VSP in contact with the surface 25s of the cover member 25 instead of the vacuum region VSP in contact with the surface WSu of the sample W. For convenience of explanation, FIG. 51 shows an example in which the scanning electron microscope SEMa of the first embodiment irradiates the sample W covered with the cover member 25 described in the third modification with the electron beam EB. However, each of the scanning electron microscope SEMb of the second embodiment to the scanning electron microscope SEMo of the fifteenth embodiment also irradiates the sample W covered with the cover member 25 described in the third modification with the electron beam EB. Needless to say, it may be done.

In the third modification, the sample W may have a size small enough that the vacuum region VSP can cover the entire surface WSu of the sample W, or the vacuum region VSP is of the surface WSu of the sample W. It may have a size large enough to cover only a part of.

In the third modification, at least one of the scanning electron microscope SEMa of the first embodiment to the scanning electron microscope SEMo of the fifteenth embodiment has a desired distance D between the injection surface 12LS and the surface WSu. Instead, at least the interval adjusting system 14 (or the position adjusting system 14 g) and the stage drive system 23 so that the interval Do2 between the injection surface 12LS and the surface 25s of the cover member 25 becomes the desired interval D_taget. One may be controlled.

Further, in at least one of the scanning electron microscope SEMg of the seventh embodiment to the scanning electron microscope SEMk of the eleventh embodiment in which the position control operation is performed, the distance D between the injection surface 12LS and the surface WSu is a desired distance D_target. And / or instead of performing the position control operation so that the injection surface 12LS and the surface WSu are parallel to each other, the distance Do2 between the injection surface 12LS and the surface 25s of the cover member 25 is a desired distance D_target. The position control operation may be performed so that the ejection surface 12LS and the surface 25s are parallel to each other. For example, at least one of the scanning electron microscopes SEMg to SEMk estimates the position of the injection surface 12LS (steps S11 to S13 in FIG. 22) and measures the position of the surface 25s of the cover member 25s in the first control operation. (Process corresponding to step S15 in FIG. 22), The positional relationship between the beam irradiation device 1 and the stage 22 so that the injection surface 12LS and the surface 25s of the cover member 25s are parallel and the interval Do2 is the desired interval D_taget. May be controlled (process corresponding to step S17 in FIG. 22). As a result, at least one of the scanning electron microscopes SEMg to SEMk is in a state where the injection surface 12LS and the surface 25s are parallel and the interval Do2 is the desired interval D_target even if the second control operation is not necessarily performed. The sample W can be irradiated with an electron beam EB.

Alternatively, if the sample W is not held by the stage 22, the cover member 25 for covering the sample W may also not be arranged on the stage 22. In this case, in at least one of the scanning electron microscopes SEMg to SEMk, in the first control operation, the distance D'between the surface WSuv of the virtual sample Wv and the injection surface 12LS becomes the desired distance D_taget and is injected. The surface WSuv is parallel to the surface 12LS, or the distance Do1 between the outer peripheral surface OS and the injection surface 12LS is a desired distance D_taget and the outer peripheral surface OS is parallel to the injection surface 12LS. , The positional relationship between the beam irradiation device 1 and the stage 22 may be controlled. On top of that, at least one of the scanning electron microscopes SEMg to SEMk is used after the stage 22 holds the sample W and the cover member 25 is arranged on the stage 22 in the first control operation (in step S21 of FIG. 29). (Corresponding process), the position of the surface 25s of the cover member 25 is measured (process corresponding to step S22 in FIG. 29), the distance Do2 between the surface 25s and the injection surface 12LS becomes the desired distance D_target, and the injection surface. The positional relationship between the beam irradiation device 1 and the stage 22 may be controlled so that the surface 25s is parallel to the 12LS (process corresponding to step S23 in FIG. 29). As a result, the scanning electron microscope SEMg to SEMk can irradiate the sample W with the electron beam EB in a state where the injection surface 12LS and the surface 25s are parallel to each other and the interval Do2 is the desired interval D_taget.

Even when the scanning electron microscope SEMl of the twelfth embodiment provided with the above-mentioned optical microscope 17l irradiates the sample W covered with the cover member 25 described in the third modification with the electron beam EB, the twelfth embodiment is carried out. As described in the embodiment, during at least a part of the period (that is, the optical measurement period) in which the sample W is located at a position where the optical microscope 17l can measure the state of the sample W, the beam irradiator 1 sets the stage 22. A vacuum region VSP may be formed between the surface of the surface (for example, the outer peripheral surface OS). Further, after the optical measurement period is completed, the stage 22 is XY from a state in which the optical microscope 17l can measure the sample W and the beam irradiation device 1 can form a vacuum region VSP with the outer peripheral surface OS. It may move along a plane. As a result, the beam irradiation device 1 can irradiate the sample W with the electron beam EB via the vacuum region VSP. The height of the outer peripheral surface OS (that is, the position in the Z-axis direction) may be the same as the height of the surface 25s of the cover member 25. In this case, it is possible to reduce the possibility that the vacuum region VSP is destroyed when the vacuum region VSP crosses the boundary between the outer peripheral surface OS and the surface 25s of the cover member 25 as the stage 22 moves. Therefore, the throughput of the scanning electron microscope SEMl is improved.

(15-4) Fourth Modified Example In the fourth modified example, at least one of the vacuum pumps 51 and 52 (or the pump constituting at least one of the vacuum pumps 51 and 52) and the beam irradiation device 1 included in the pump system 5 May be connected so that the transmission of vibration from at least one of the vacuum pumps 51 and 52 (or the pump constituting at least one of the vacuum pumps 51 and 52) to the beam irradiator 1 is suppressed. Hereinafter, an example of a connection mode between the vacuum pump 51 and the beam irradiation device 1 in which the transmission of vibration from the vacuum pump 51 to the beam irradiation device 1 is suppressed will be described with reference to FIG. 52. FIG. 52 is a cross-sectional view showing a connection mode between the vacuum pump 51 and the beam irradiation device 1 in which the transmission of vibration from the vacuum pump 51 to the beam irradiation device 1 is suppressed.

As described above, the vacuum pump 51 and the beam irradiation device 1 are connected via the pipe 117. As shown in FIG. 52, the pipe 117 includes a pipe 1171 extending from the vacuum pump 51 toward the beam irradiation device 1 and a pipe 1172 extending from the beam irradiation device 1 toward the vacuum pump 51. The pipe 1171 is provided with a flange portion 11711 at its tip. The pipe 1172 is provided with a flange portion 11721 at its tip. The flange portion 11711 faces the flange portion 11721 via the facing surface 11712. The flange portion 11712 faces the flange portion 11711 via the facing surface 11722. The

pipes

1171 and 1172 are arranged so that the facing surface 11712 of the flange portion 11711 and the facing surface 11722 of the flange portion 11721 face each other via the O-ring 1181 and the center ring 1182 (or any other elastic member). That is, the O-ring 1181 and the center ring 1182 are arranged between the facing surface 11712 of the flange portion 11711 and the facing surface 11722 of the flange portion 11721.

The

flange portions

11711 and 11721 are fixed by the

clamp members

1181 and 1182 in a state of being sandwiched by the

clamp members

1183 and 1184. The

clamp members

1183 and 1184 are fixed by nuts 1185 and bolts 1186. At this time, an O-ring 1187 (or any other elastic member) is arranged between the clamp member 1183 and the pipe 1171 (particularly, the flange portion 11711). That is, the clamp member 1183 applies a force for fixing the pipe 1171 and the pipe 1172 to the pipe 1171 via the O-ring 1187. Further, an O-ring 1188 (or any other elastic member) is arranged between the clamp member 1184 and the pipe 1172 (particularly, the flange portion 11721). That is, the clamp member 1184 applies a force for fixing the pipe 1171 and the pipe 1172 to the pipe 1172 via the O-ring 1188.

As described above, in the fourth modification, the O-ring 1181 and the center ring 1182 are arranged between the pipe 1171 and the pipe 1172. Therefore, the vibration transmitted from the vacuum pump 51 to the pipe 1171 is absorbed by the O-ring 1181 and the center ring 1182 before being transmitted to the pipe 1172. As a result, the transmission of vibration from the vacuum pump 51 to the beam irradiation device 1 via the

pipes

1171 and 1172 is suppressed by the O-ring 1181 and the center ring 1182.

Further, an O-ring 1187 is arranged between the pipe 1171 and the clamp member 1183. Therefore, the vibration transmitted from the vacuum pump 51 to the pipe 1171 is absorbed by the O-ring 1187 before being transmitted to the clamp member 1183. Further, an O-ring 1188 is arranged between the pipe 1172 and the clamp member 1184. Therefore, even if the vibration is transmitted from the vacuum pump 51 to the

clamp members

1183 and 1184 via the pipe 1171, the vibration transmitted to the clamp member 1184 is absorbed by the O-ring 1188 before being transmitted to the pipe 1172. To. As a result, the transmission of vibration from the vacuum pump 51 to the beam irradiation device 1 via the

pipes

1171 and 1172 and the

clamp members

1183 and 1184 is suppressed by the O-

rings

1187 and 1188.

Here, the O-ring 1187 makes point contact with the pipe 1171 and the clamp member 1183 or makes contact with a relatively narrow surface, and the O-ring 1188 makes point contact with the pipe 1172 and the clamp member 1184 or makes contact with a relatively narrow surface. Contact. As a result, the O-ring 1187 rotates between the pipe 1171 and the clamp member 1183 and / or the O-ring 1188 rotates between the pipe 1172 and the clamp member 1184, whereby the

clamp members

1183 and 1184 and the pipe 1171 and There is a possibility that the relative position with 1172 will change. Therefore, positioning of the

clamp members

1183 and 1184 and the

pipes

1171 and 1172 may become difficult. Therefore, in addition to or in place of the O-ring 1187, an elastic member capable of surface contact with the pipe 1171 and the clamp member 1183 (particularly, contactable with a relatively wide surface) is arranged between the pipe 1171 and the clamp member 1183. It may have been done. In addition to or in place of the O-ring 1188, a surface contactable (particularly, relatively wide surface) elastic member is arranged between the pipe 1172 and the clamp member 1184 to contact the pipe 1171 and the clamp member 1183. You may. For example, FIG. 53 is a cross-sectional view showing an example in which a rubber sheet 1189, which is a specific example of an elastic member, is arranged between the pipe 1172 and the clamp member 1184 in addition to or in place of the O-ring 1188. As a result, the positioning of the

clamp members

1183 and 1184 and the

pipes

1171 and 1172 becomes relatively easy.

The connection mode between the vacuum pump 52 and the beam irradiation device 1 in which the transmission of vibration from the vacuum pump 52 to the beam irradiation device 1 is suppressed is such that the transmission of vibration from the vacuum pump 51 to the beam irradiation device 1 is suppressed. It may be the same as the connection mode between the 51 and the beam irradiation device 1. Therefore, the detailed description thereof will be omitted.

(15-5) Other Modifications In the above description, the differential exhaust system 12 is a one-stage differential exhaust system including a single exhaust mechanism (specifically, an exhaust groove 124 and a pipe 125). is there. However, the differential exhaust system 12 may be a multi-stage differential exhaust system including a plurality of exhaust mechanisms. In this case, a plurality of exhaust grooves 124 are formed on the injection surface 12LS of the vacuum forming member 121, and a plurality of pipes 125 connected to the plurality of exhaust grooves 124 are formed on the vacuum forming member 121. Each of the plurality of pipes 125 is connected to a plurality of vacuum pumps 52 included in the pump system 5. The exhaust capacities of the plurality of vacuum pumps 52 may be the same or different.

Not limited to the scanning electron microscope SEM, any electron beam device that irradiates the sample W (or any other object) with the electron beam EB is the fifteenth embodiment from the scanning electron microscope SEMa of the first embodiment described above. It may have a structure similar to at least one of the scanning electron microscope SEMO of the form. That is, any electron beam device controls the distance between the beam irradiation device that irradiates the electron beam EB and the object that is irradiated with the electron beam EB through the opening facing the beam passage space SPb (or ) The degree of vacuum of at least a part of the beam passing space SPb may be controlled. An arbitrary electron beam device performs the above-mentioned position control operation (that is, a position control operation for controlling the positional relationship between the beam irradiation device that irradiates the electron beam EB and the stage based on the measurement result of the measurement device 8g). You may. As an example of an arbitrary electron beam device, the electron beam exposure device that forms a pattern on the wafer by exposing the wafer coated with the electron beam resist using the electron beam EB, and the electron beam EB are irradiated to the base material. At least one of the electron beam welding devices that welds the base metal with the heat generated by the metal beam welder can be mentioned. As another example of the arbitrary electron beam apparatus, there are a transmission electron microscope (TEM: Transmission Electron Microscope) and a scanning transmission electron microscope (STEM: Scanning Transmission Electron Microscope).

Alternatively, not limited to the electron beam device, any beam device that irradiates an arbitrary sample W (or any other object) with an arbitrary charged particle beam or energy beam different from the electron beam EB is the first embodiment described above. It may have the same structure as at least one of the scanning electron microscope SEMa of the embodiment to the scanning electron microscope SEMo of the fifteenth embodiment. That is, any beam device equipped with a beam optical system capable of irradiating a charged particle beam or energy beam can pass through an opening facing the beam passage space through which the charged particle beam or energy beam passes (or the charged particle beam or energy). The degree of vacuum of at least a portion of the beam passage space may be controlled (by controlling the distance between the beam irradiator that irradiates the beam and the object that is irradiated with the charged particle beam or energy beam). Any beam device equipped with a beam optical system capable of irradiating a charged particle beam or an energy beam irradiates a charged particle beam or an energy beam based on the position control operation described above (that is, the measurement result of the measuring device 8 g). A position control operation) for controlling the positional relationship between the device and the stage may be performed. As an example of an arbitrary beam device, a focused ion beam (FIB: Focused Ion Beam) device that irradiates a sample with a focused ion beam for processing and observation, and a soft X-ray region (for example, a wavelength range of 5 to 15 nm). At least one of the EUV exposure devices that form a pattern on a wafer by exposing a wafer coated with a resist using EUV (Extreme Ultraviolet) light can be mentioned.

Alternatively, the first embodiment described above is not limited to the beam device, and any irradiation device that irradiates an arbitrary sample W (or any other object) with an arbitrary charged particle containing an electron in an irradiation form different from the beam. It may have a structure similar to at least one of the scanning electron microscope SEMa of the embodiment to the scanning electron microscope SEMo of the fifteenth embodiment. That is, any irradiator equipped with an irradiation system capable of irradiating (eg, emitting, generating, ejecting or) charged particles can (or radiate) the charged particles through an opening facing the charged particle passage space through which the charged particles pass. The degree of vacuum of at least a part of the charged particle passage space may be controlled (by controlling the distance between the beam irradiator to be irradiated and the object to which the charged particles are irradiated). Irradiation in which any irradiation device provided with an irradiation system capable of irradiating (for example, emitting, generating, ejecting or) charged particles irradiates the charged particles based on the above-mentioned position control operation (that is, the measurement result of the measuring device 8 g). A position control operation) for controlling the positional relationship between the device and the stage may be performed. As an example of an arbitrary irradiation device, an etching device that etches an object using plasma, and a film forming device (for example, a PVD (Physical Vapor Deposition) device such as a sputtering device) that performs a film forming process on an object using plasma. And at least one of CVD (Chemical Vapor Deposition) apparatus).

Alternatively, the scanning type of the first embodiment described above is an arbitrary vacuum device that causes an arbitrary sample W (or any other object) to act under a vacuum in a form different from irradiation, not limited to charged particles. It may have the same structure as at least one of the scanning electron microscope SEMo of the fifteenth embodiment from the electron microscope SEMa. An example of an arbitrary vacuum device is a vacuum vapor deposition device that forms a film by allowing vapor of a material evaporated or sublimated in a vacuum to reach a sample and accumulate it.

At least a part of the constituent elements of each of the above-described embodiments (including each modification, the same shall apply hereinafter in this paragraph) can be appropriately combined with at least another part of the constituent requirements of each of the above-described embodiments. Some of the constituent requirements of each of the above embodiments may not be used. In addition, to the extent permitted by law, all publications cited in each of the above embodiments and disclosures of US patents shall be incorporated as part of the text.

The present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of claims and within the scope not contrary to the gist or idea of the invention that can be read from the entire specification, and the charged particle device accompanied by such modification. , A method of irradiating charged particles, a vacuum forming apparatus, and a method of forming a vacuum region are also included in the technical scope of the present invention.

SEM scanning electron microscope 1 Beam irradiation device 11 Beam optical system 12 Differential exhaust system 121LS Exit surface 1232

Beam injection port

126, 126b,

126c Opening

1281, 1282 Valve 13 Flange member 14 Spacing adjustment system 14g Position adjustment system 16d Aperture member 161d Opening 2 Stage device 22 Stage 23 Stage drive system 4 Control device 5

Pump system

51, 52 Vacuum pump 6 Gas supply device 7 Exhaust device 8g Measuring device SPb1, SPb2, SPb3 Beam passage space VSP Vacuum area W Sample WSu Surface HS holding surface

Claims

A vacuum forming member having a first pipeline that can be connected to an exhaust device and discharging gas in a space in contact with the surface of an object through the first pipeline to form a vacuum region.
An irradiation device that irradiates a sample with charged particles through the vacuum region,
A second conduit connected to the passage space of the charged particles irradiated from the irradiation device, and
With
The air pressure is higher than that of the vacuum region, and at least a part of the gas in the space around the vacuum region is discharged through the first pipeline of the vacuum forming member.
The passage space includes at least a part of the vacuum region.
A charged particle device that supplies gas to at least a part of the passage space through the second pipeline.
A first conduit having a first end connected to an exhaust device and a second end connected to a first space in contact with the surface of an object is provided, and the gas in the first space is passed through the first conduit. A vacuum forming member that discharges through the first space to form a vacuum region having a lower pressure than the second space connected to the first space in the first space.
An irradiation device that irradiates a sample with charged particles through a vacuum region of the charged particles emitted from the irradiation device, and an irradiation device.
A second pipeline connecting to the passage space,
With
The passage space includes at least a part of the vacuum region.
A charged particle device that supplies gas to at least a part of the passage space through the second pipeline.
By having a first pipeline that can be connected to an exhaust device and discharging gas through the first pipeline in a state of facing a part of the surface of the object, the first of the surface of the object. A vacuum forming member capable of forming a vacuum region having a pressure lower than the pressure of the second space in contact with the second portion different from the first portion of the surface in the first space in contact with the portion.
An irradiation device that irradiates a sample with charged particles through the vacuum region,
A second conduit connected to the passage space of the charged particles irradiated from the irradiation device, and
With
The passage space includes at least a part of the vacuum region.
A charged particle device that supplies gas to at least a part of the passage space through the second pipeline.
The charged particle according to claim 2 or 3, wherein the second space cannot be connected to the first pipeline without passing through the first space, but can be connected to the first pipeline after passing through the first space. apparatus.
The charged particle device according to any one of claims 2 to 4, wherein the first space is located between the second space and the first pipeline.
The first pipeline has a first pipeline that can be connected to an exhaust device, and a gas in a space in contact with the surface of the object is used in a state where the surface of the object and the end of the first pipeline face each other. A vacuum forming member that discharges through a pipeline to form a vacuum region,
An irradiation device that irradiates a sample with charged particles through the vacuum region,
A second conduit connected to the passage space of the charged particles irradiated from the irradiation device, and
With
The passage space includes at least a part of the vacuum region.
A charged particle device that supplies gas to at least a part of the passage space through the second pipeline.
Claims 1 to 6 for controlling the distance between the object and the vacuum forming member in parallel with controlling the degree of vacuum of at least a part of the passing space by supplying gas through the second pipeline. The charged particle apparatus according to any one item.
In parallel with reducing the degree of vacuum of at least a part of the passage space by supplying gas through the second pipeline, the force applied in the direction of separating the object and the vacuum forming member is reduced. The charged particle apparatus according to any one of claims 1 to 7.
In parallel with reducing the degree of vacuum of at least a part of the passage space by supplying gas through the second pipeline, the force applied in the direction of bringing the object and the vacuum forming member closer to each other is increased. The charged particle apparatus according to any one of claims 1 to 8.
Any one of claims 1 to 9 that brings the object and the vacuum forming member closer to each other in parallel with reducing the degree of vacuum of at least a part of the passing space by supplying gas through the second pipeline. The charged particle apparatus according to the section.
The object and the object before and after reducing the vacuum degree of at least a part of the passing space in parallel with reducing the vacuum degree of at least a part of the passing space by supplying gas through the second pipeline. The charged particle apparatus according to any one of claims 1 to 10, which maintains a distance between the vacuum forming member and the vacuum forming member.
The charged particle device according to any one of claims 1 to 11, wherein the passage space can be connected to a low vacuum space having a lower degree of vacuum than the passage space via the second pipeline.
The charged particle device according to claim 12, wherein the air pressure in the low vacuum space is equal to the air pressure around the charged particle device.
The charged particle device according to claim 13, wherein the pressure around the charged particle device is atmospheric pressure.
The charged particle device according to any one of claims 1 to 14, further comprising a gas supply device for supplying gas to the passage space through the second pipeline.
The charged particle device according to claim 15, wherein the gas supplied by the gas supply device includes at least one of helium, neon, argon, nitrogen, and clean dry air (CDA).
The charged particle apparatus according to any one of claims 1 to 16, wherein gas is discharged from at least a part of the passing space through a second pipeline connected to the passing space.
A vacuum forming member having a first pipeline that can be connected to an exhaust device and discharging gas in a space in contact with the surface of an object through the first pipeline to form a vacuum region.
An irradiation device that irradiates a sample with charged particles through the vacuum region,
A second conduit connected to the passage space of the charged particles irradiated from the irradiation device, and
With
The air pressure is higher than that of the vacuum region, and at least a part of the gas in the space around the vacuum region is discharged through the first pipeline of the vacuum forming member.
The passage space includes at least a part of the vacuum region.
A charged particle device that discharges gas from at least a part of the passage space through the second pipeline.
17 or 18 of claim 17 or 18, which controls the distance between the object and the vacuum forming member in parallel with controlling the degree of vacuum of at least a part of the passing space by discharging gas through the second pipeline. The charged particle device described.
In parallel with increasing the degree of vacuum of at least a part of the passage space by discharging gas through the second pipeline, the force applied in the direction of separating the object and the vacuum forming member is increased. The charged particle apparatus according to any one of claims 17 to 19.
In parallel with increasing the degree of vacuum of at least a part of the passage space by discharging gas through the second pipeline, the force applied in the direction of bringing the object and the vacuum forming member closer to each other is reduced. The charged particle apparatus according to any one of claims 17 to 20.
Any one of claims 17 to 21 that separates the object from the vacuum forming member in parallel with increasing the degree of vacuum of at least a part of the passage space by discharging gas through the second pipeline. The charged particle apparatus according to the section.
The object and the object before and after increasing the degree of vacuum of at least a part of the passage space in parallel with increasing the degree of vacuum of at least a part of the passage space by discharging gas through the second pipeline. The charged particle apparatus according to any one of claims 17 to 22, which maintains a distance from a vacuum forming member.
The charged particle device according to any one of claims 17 to 23, wherein the passage space can be connected to a high vacuum space having a higher degree of vacuum than the passage space via the second pipeline.
The charged particle device according to any one of claims 17 to 24, comprising an exhaust device for discharging at least a part of gas in the passage space through the second pipeline.
The charged particle device according to any one of claims 1 to 25, wherein the second pipeline is connected to a valve that controls the degree of vacuum of at least a part of the passage space.
The distance between the object and the vacuum forming member is controlled in parallel with controlling the degree of vacuum of at least a part of the passage space by at least one of gas supply and gas discharge through the second pipeline. The charged particle apparatus according to any one of claims 1 to 26.
Any one of claims 1 to 27, wherein the end portion of the second pipeline on the vacuum region side is located on the opposite side of the object from the end of the first pipeline on the vacuum region side. The charged particle apparatus according to.
The charged particle device according to any one of claims 1 to 28, wherein the passage space includes a space between the irradiation device and the end of the first pipeline on the vacuum region side.
Any of claims 1 to 29, wherein the end of the second pipeline on the vacuum region side is connected to a space between the irradiation device and the end of the first pipeline on the vacuum region side. The charged particle apparatus according to one item.
The charge according to claim 29 or 30, wherein the space included in the passage space between the irradiation device and the end of the first pipeline on the vacuum region side is formed in the vacuum forming member. Particle device.
The charged particle device according to any one of claims 1 to 31, wherein at least a part of the second pipeline is provided in the vacuum forming member.
The charged particle device according to any one of claims 1 to 32, wherein at least a part of the second pipeline is provided in the irradiation device.
The irradiation device irradiates the sample with the charged particles in a state where the degree of vacuum at the end of the first line is higher than the degree of vacuum at the end of the second line. 33. The charged particle apparatus according to any one of 3.
The charged particle apparatus according to any one of claims 1 to 34, wherein the second pipeline includes a filter for filtering a gas passing through the second pipeline toward the passage space.
An irradiation device that irradiates a sample with charged particles,
It has a first pipeline that can be connected to an exhaust device, and is provided with a vacuum forming member that forms a vacuum region by discharging gas in a space in contact with the surface of an object through the first pipeline.
The passage space of the charged particles irradiated from the irradiation device includes at least a part of the vacuum region.
A charged particle device that controls the distance between the object and the vacuum forming member in parallel with controlling the degree of vacuum of at least a part of the passing space.
The charged particle device according to claim 36, wherein the degree of vacuum of at least a part of the passing space is controlled by controlling the distance between the object and the vacuum forming member.
The charged particle apparatus according to claim 36 or 37, wherein the degree of vacuum of at least a part of the passing space is reduced by controlling the distance between the object and the vacuum forming member.
The charged particle apparatus according to any one of claims 36 to 38, wherein the force applied in the direction of separating the object and the vacuum forming member is increased to reduce the degree of vacuum of at least a part of the passing space. ..
The charged particle apparatus according to any one of claims 36 to 39, wherein the force applied in the direction of bringing the object and the vacuum forming member closer to each other is reduced to reduce the degree of vacuum of at least a part of the passing space. ..
The charged particle apparatus according to any one of claims 36 to 40, wherein the object and the vacuum forming member are separated to reduce the degree of vacuum of at least a part of the passing space.
The charged particle apparatus according to any one of claims 36 to 41, wherein the degree of vacuum of at least a part of the passing space is increased by controlling the distance between the object and the vacuum forming member.
The charged particle apparatus according to any one of claims 36 to 42, wherein the force applied in the direction of bringing the object and the vacuum forming member closer to each other is increased to increase the degree of vacuum of at least a part of the passing space. ..
The charged particle apparatus according to any one of claims 36 to 43, wherein the force applied in the direction of separating the object and the vacuum forming member is reduced to increase the degree of vacuum of at least a part of the passing space. ..
The charged particle apparatus according to any one of claims 36 to 44, wherein the object and the vacuum forming member are brought close to each other to increase the degree of vacuum of at least a part of the passing space.
The charged particle apparatus according to any one of claims 36 to 45, wherein the distance between the object and the vacuum forming member is controlled in parallel with controlling the degree of vacuum of at least a part of the passing space.
A gas supply device for supplying gas to a peripheral region located at least a part around the vacuum region is provided.
The charged particle device according to any one of claims 1 to 46, wherein the gas supplied by the gas supply device includes at least one of helium, neon, argon, nitrogen, and clean dry air (CDA).
One of claims 36 to 47, which can be set to a first mode in which the vacuum region is used in the first pressure range and a second mode in which the vacuum region is used in a second pressure range different from the first pressure range. The charged particle apparatus according to the section.
A vacuum forming member having a first pipeline that can be connected to an exhaust device and discharging gas in a space in contact with the surface of an object through the first pipeline to form a vacuum region.
An irradiation device that irradiates a sample with charged particles through the vacuum region,
With
At least a part of the gas in the space around the vacuum region having a higher atmospheric pressure than the vacuum region is discharged through the first pipeline of the vacuum forming member.
The passage space of the charged particles irradiated from the irradiation device includes at least a part of the vacuum region.
A charged particle device that can be set to a first mode in which the vacuum region is used in a first pressure range and a second mode in which the vacuum region is used in a second pressure range different from the first pressure range.
The charged particle apparatus according to claim 48 or 49, wherein the distance between the object and the vacuum forming member is substantially the same in the first mode and the second mode.
The charged particle device according to claim 48 or 49, wherein the distance between the object and the vacuum forming member in the first mode is different from the distance between the object and the vacuum forming member in the second mode.
The charged particle apparatus according to claim 51, which changes from one of the first mode and the second mode to the other by changing the distance between the object and the vacuum forming member.
It is provided with a second pipeline that connects to the passage space.
The charged particle apparatus according to any one of claims 48 to 52, wherein a change from one of the first mode and the second mode to the other is performed by using the second pipeline.
The charged particle apparatus according to claim 53, wherein at least a part of the second pipeline is provided in the vacuum forming member.
The charged particle device according to claim 54, wherein one end of the second pipeline is arranged so that the surfaces of the objects face each other.
Any one of claims 1 to 35, which can be set to a first mode in which the vacuum region is used in the first pressure range and a second mode in which the vacuum region is used in a second pressure range different from the first pressure range. The charged particle apparatus according to the section.
The charged particle device according to claim 56, wherein the distance between the object and the vacuum forming member is substantially the same in the first mode and the second mode.
The charged particle apparatus according to claim 56, wherein the distance between the object and the vacuum forming member in the first mode is different from the distance between the object and the vacuum forming member in the second mode.
The charged particle device according to claim 58, which changes from one of the first mode and the second mode to the other by changing the distance between the object and the vacuum forming member.
The amount of gas supplied to the passage space via the second pipeline in the first mode and the amount of gas supplied to the passage space via the second pipeline in the second mode are determined. The charged particle apparatus according to any one of different claims 53 to 59.
One of claims 53 to 60, which changes from one of the first mode and the second mode to the other by changing the amount of gas supplied to the passage space through the second pipeline. The charged particle device described in one line.
The amount of gas discharged from the passage space through the second pipeline in the first mode and the amount of gas discharged from the passage space through the second pipeline in the second mode. The charged particle apparatus according to any one of claims 53 to 61, wherein the charged particle apparatus is different.
Any of claims 53 to 62, which changes from one of the first mode and the second mode to the other by changing the amount of gas discharged from the passage space through the second pipeline. The charged particle device described in one line.
Claims 48 to 63, wherein the amount of gas discharged through the first pipeline in the first mode and the amount of gas discharged through the first pipeline in the second mode are different. The charged particle apparatus according to any one line.
The charged particle apparatus according to claim 64, wherein the change from one of the first mode and the second mode to the other is performed by changing the amount of gas discharged through the first pipeline.
The passage space includes a first passage space formed in the irradiation device and a second passage space in contact with the surface of the object.
The charged particle apparatus according to any one of claims 1 to 65, further comprising an opening through which the charged particles can pass between the first passing space and the second passing space.
The charged particle apparatus according to claim 66, wherein the difference between the degree of vacuum in the first passing space and the degree of vacuum in the second passing space is maintained by the exhaust resistance of the opening.
The charged particle apparatus according to claim 66 or 67, wherein the area of the opening is variable.
The charged particle apparatus according to any one of claims 66 to 68, wherein the area of the opening is changed in parallel with changing the degree of vacuum of at least a part of the passing space.
According to any one of claims 66 to 69, the area of the opening is reduced in parallel with increasing the difference between the degree of vacuum of the first passing space and the degree of vacuum of the second passing space. The charged particle device described.
The degree of vacuum of the first passing space is higher than the degree of vacuum of the second passing space.
The charged particle apparatus according to any one of claims 66 to 70, wherein the area of the opening is reduced in parallel with reducing the degree of vacuum of the second passage space.
According to any one of claims 66 to 71, the area of the opening is increased in parallel with reducing the difference between the degree of vacuum of the first passing space and the degree of vacuum of the second passing space. The charged particle device described.
The degree of vacuum of the first passing space is higher than the degree of vacuum of the second passing space.
The charged particle apparatus according to any one of claims 66 to 72, wherein the area of the opening is increased in parallel with increasing the degree of vacuum of the second passage space.
The irradiation device includes a lens for charged particles that guides the charged particles toward the sample.
The charged particle device according to any one of claims 66 to 73, wherein the aperture is located inside the lens for charged particles.
The aperture is closer to the axis of the charged particle lens than the charged particle lens and is located between the upper and lower ends of the charged particle lens in a direction along the axis of the charged particle lens. The charged particle apparatus according to claim 74.
The charged particle device according to any one of claims 66 to 75, wherein the opening is located at a deflection fulcrum of a deflector included in the irradiation device.
A charged particle detector for detecting charged particles from a sample irradiated with the charged particles is provided.
The charged particle device according to any one of claims 66 to 76, wherein the charged particle detector is located between the opening and the sample.
A charged particle detector for detecting charged particles from a sample irradiated with the charged particles is provided.
The passage space between the sample and the charged particle detector, with respect to the direction along the surface of the object as the charged particles move away from the irradiated sample in a direction intersecting the surface of the object. The charged particle apparatus according to any one of claims 1 to 76, wherein the charged particles of the sample are spread away from the irradiated position.
The charged particle apparatus according to any one of claims 1 to 78, wherein the degree of vacuum of at least a part of the passage space when the sample is an insulator is smaller than that when the sample is not an insulator.
The charged particle apparatus according to any one of claims 1 to 79, wherein the distance between the object and the vacuum forming member when the sample is an insulator is larger than that when the sample is not an insulator.
When the vacuum region is formed so as to cover a part of the surface of the object, the other part of the surface of the object is covered with a non-vacuum region or a region having a lower degree of vacuum than the vacuum region. The charged particle apparatus according to any one of Items 1 to 80.
The charged particle apparatus according to any one of claims 1 to 81, wherein at least a part of the surface of the object faces at least a part of the vacuum region.
The charged particle apparatus according to any one of claims 1 to 82, wherein at least a part of the surface of the object is covered with at least a part of the vacuum region.
The charged particle according to any one of claims 1 to 83, wherein a part of the surface of the object faces the vacuum region and the other part of the surface of the object faces the atmospheric pressure region. apparatus.
The charged particle apparatus according to any one of claims 1 to 84, wherein the surface of the object includes at least a part of the surface of the sample.
The charged particle apparatus according to any one of claims 1 to 84, wherein the surface of the object includes at least a part of the surface of a holding member that holds the sample.
The charged particle apparatus according to any one of claims 1 to 84, wherein the surface of the object includes at least a part of the surface of the member arranged between the sample and the vacuum forming member.
The charged particle apparatus according to any one of claims 1 to 87, comprising a vacuum gauge for acquiring at least a part of the pressure between the first pipeline and the passing space.
The charged particle apparatus according to any one of claims 1 to 87, which controls the distance between the object and the vacuum forming member based on the degree of vacuum acquired by the vacuum system.
Using a vacuum forming member having a first pipeline that can be connected to an exhaust device, gas in a space in contact with the surface of an object is discharged through the first pipeline to form a vacuum region.
Discharging at least a part of the gas in the space around the vacuum region, which has a higher atmospheric pressure than the vacuum region, through the first pipeline.
Irradiating the sample with charged particles that have passed through the passage space including at least a part of the vacuum region.
A method of irradiating charged particles that controls the distance between the object and the vacuum forming member in parallel with controlling the degree of vacuum of at least a part of the passing space.
The charged particles are applied to the sample through the passage space formed in the vacuum forming member.
The degree of vacuum of at least a part of the passage space due to at least one of gas supply and gas discharge through the second pipeline connected to the passage space, which is a pipeline different from the first pipeline. The method of irradiating a charged particle according to claim 90.
The method for irradiating charged particles according to claim 90 or 91, wherein the distance between the object and the vacuum forming member is controlled in parallel with controlling the degree of vacuum of at least a part of the passing space.
The vacuum forming member forms the vacuum region in a space between an object having a first surface and having a second surface facing the first surface.
The invention according to any one of claims 1 to 89, further comprising a position changing device for changing the positional relationship between the first surface and the second surface based on either the posture and the shape of the first surface. Charged particle device
The charged particle device according to claim 93, wherein the irradiation device irradiates the charged particles toward the sample from the injection port formed on the first surface.
The charged particle apparatus according to claim 94, wherein the injection port includes an end portion of the first pipeline on the vacuum region side.
A gas in a space having a first pipeline and a first surface that can be connected to an exhaust device and in contact with a second surface of an object that can face the first surface is discharged through the first pipeline. Then, the vacuum forming member that forms the vacuum region and
An irradiation device that irradiates a sample with charged particles from an injection port formed on the first surface.
A position changing device for changing the positional relationship between the first surface and the second surface based on either the posture or the shape of the first surface is provided.
At least a part of the gas in the space around the vacuum region having a higher atmospheric pressure than the vacuum region is discharged through the first pipeline of the vacuum forming member.
A charged particle device in which the passage of charged particles irradiated from the charged particle irradiation device includes at least a part of the vacuum region.
The charged particle device according to claim 96, wherein the opening at one end of the first pipeline is formed on the first surface.
The charged particle apparatus according to claim 96 or 97, wherein the posture of the first surface includes information in the normal direction of the first surface.
The position change device according to any one of claims 96 to 98, which changes the positional relationship between the first surface and the second surface based on either the posture and the shape of the second surface. Charged particle device.
The charged particle device according to claim 99, wherein the posture of the second surface includes information in the normal direction of the second surface.
The positional relationship between the first surface and the second surface is at least the distance between the first surface and the second surface and the relative relationship between the posture of the first surface and the posture of the second surface. The charged particle apparatus according to any one of claims 96 to 100, which includes one.
The electric charge according to claims 96 to 101, wherein the position changing device changes the positional relationship so that the first surface and the second surface are closer to parallel than before the positional relationship is changed. Particle device.
The charged particle device according to any one of claims 96 to 102, wherein the position changing device changes the positional relationship so that the first surface and the second surface are parallel to each other.
The charged particle device according to any one of claims 96 to 103, wherein the position changing device changes the positional relationship so as to prevent contact between the first surface and the second surface.
One of the postures and shapes of the first surface is such that the first surface and the third surface come into contact with a reference member having a third surface that can include at least a part of the first surface. The charged particle device according to any one of claims 96 to 104, which is indirectly detected by bringing the vacuum forming member into contact with the vacuum forming member and irradiating the third surface with a detection beam from the detection device.
A storage device for storing information regarding either the posture or the shape of the first surface is provided.
The position changing device changes the positional relationship between the first surface and the second surface based on the information about one of the posture and the shape of the first surface stored in the storage device. 10. The charged particle apparatus according to any one of 105.
The charged particle device according to any one of claims 96 to 106, comprising a detection device for detecting either one of the posture and the shape of the first surface.
The charged particle device according to claim 107, wherein the detection device detects either one of the posture and the shape of the second surface.
The charged particle device according to claim 108, wherein the detection device uses the same detector to detect one of the postures and shapes of the first surface and the second surface.
The charged particle device according to claim 109, wherein the detector is arranged at a first position fixed to the vacuum forming member.
The positional relationship between the detector and the vacuum forming member when detecting either one of the posture and shape of the first surface is the detection when detecting either one of the posture and shape of the second surface. The charged particle apparatus according to claim 109 or 110, which has the same positional relationship with respect to the vacuum forming member of the vessel.
The charged particle device according to any one of claims 109 to 111, wherein the detector is arranged at a first position fixed to the irradiation device.
The positional relationship between the detector and the irradiation device when detecting either one of the posture and the shape of the first surface is the same as the detector when detecting one of the posture and the shape of the second surface. The charged particle device according to claim 112, which has the same positional relationship as that of the irradiation device.
The charged particle device according to any one of claims 109 to 113, wherein the detector is arranged at a second position fixed to the object.
The positional relationship between the detector and the object when detecting either one of the posture and the shape of the first surface is the same as the detector when detecting either the posture and the shape of the second surface. The charged particle apparatus according to any one of claims 109 to 114, which has the same positional relationship with the object.
The charged particle device according to any one of claims 109 to 115, wherein the detector irradiates the first surface with a detection beam to detect one of the posture and the shape of the first surface.
The charged particle device according to any one of claims 109 to 116, wherein the detector irradiates the second surface with a detection beam to detect one of the posture and the shape of the second surface.
The detector is in a state in which a reference member having a fourth surface capable of including at least a part of the first surface is in contact with the vacuum forming member so that the first surface and the fourth surface are in contact with each other. The charged particle apparatus according to any one of claims 109 to 117, wherein the fourth surface is irradiated with a detection beam to detect one of the posture and the shape of the first surface.
The charged particle apparatus according to claim 118, wherein each of the first surface and the fourth surface is a flat surface.
The reference member is a first reference member.
The detector has a fifth surface that can include at least a part of the second surface, and a second reference member different from the first reference member is the second surface and the fifth surface. The charged particle according to claim 118 or 119, which irradiates the fifth surface with a detection beam to detect either the posture or the shape of the second surface in a state of being in contact with the object so as to be in contact with the object. apparatus.
The charged particle apparatus according to claim 120, wherein each of the second surface and the fifth surface is a flat surface.
The claim includes a first detector that detects one of the postures and shapes of the first surface, and a second detector that detects one of the postures and shapes of the second surface. The charged particle apparatus according to any one of 107 to 121.
One of the first and second detectors is arranged in a first position fixed to the vacuum forming member.
The charged particle apparatus according to claim 122, wherein any one of the first and second detectors is arranged at a second position fixed to the object.
One of the first and second detectors is arranged in a first position fixed to the irradiation device.
The charged particle apparatus according to claim 122 or 123, wherein the other of the first and second detectors is arranged at a second position fixed to the object.
The charged particle device according to any one of claims 122 to 124, wherein the first detector irradiates the first surface with a detection beam to detect one of the posture and the shape of the first surface.
The charged particle device according to any one of claims 122 to 125, wherein the second detector irradiates the second surface with a detection beam to detect one of the posture and the shape of the second surface.
In the first detector, a reference member having a fourth surface capable of including at least a part of the first surface contacts the vacuum forming member so that the first surface and the fourth surface come into contact with each other. The charged particle apparatus according to any one of claims 122 to 126, wherein the fourth surface is irradiated with a detection beam to detect one of the posture and the shape of the first surface.
The charged particle apparatus according to claim 127, wherein each of the first surface and the fourth surface is a flat surface.
The reference member is a first reference member.
The second detector has a fifth surface that can include at least a part of the second surface, and a second reference member different from the first reference member is the second surface and the second surface. The 127 or 128 according to claim 127 or 128, wherein the fifth surface is irradiated with a detection beam to detect either the posture or the shape of the second surface in a state of being in contact with the object so as to be in contact with the five surfaces. Charged particle device.
The charged particle apparatus according to claim 129, wherein each of the second surface and the fifth surface is a flat surface.
The first and second detectors irradiate the same sixth surface with a detection beam to further detect one of the posture and shape of the sixth surface.
After associating the detection result of one of the posture and the shape of the first surface with the detection result of one of the posture and the shape of the second surface based on the detection result of the sixth surface, the association is made. Any one of claims 122 to 130 that changes the positional relationship based on the detection result of either one of the posture and the shape of the first surface and the detection result of one of the posture and the shape of the second surface. The charged particle apparatus according to one item.
The first and second detectors irradiate two different seventh surfaces having known positional relationships with a detection beam to further detect one of the posture and shape of the seventh surface.
After associating the detection result of one of the posture and the shape of the first surface with the detection result of one of the posture and the shape of the second surface based on the detection result of the seventh surface, the association is made. Any one of claims 122 to 131 that changes the positional relationship based on the detection result of either one of the posture and the shape of the first surface and the detection result of one of the posture and the shape of the second surface. The charged particle apparatus according to one item.
Any of claims 96 to 132, wherein the position changing device changes the positional relationship before the relative position between the irradiation device and the object changes along at least one of the first surface and the second surface. The charged particle device according to one item.
The position changing device of the object with respect to the irradiation device during at least a part of a period in which the relative positions of the irradiation device and the object are changing along at least one of the first surface and the second surface. The charged particle apparatus according to any one of claims 96 to 133, wherein the positional relationship is changed according to the relative movement.
A detection device for detecting either one of the posture and shape of the first surface and one of the posture and shape of the second surface is provided.
During at least a part of the period in which the relative positions of the irradiation device and the object are changing along at least one of the first surface and the second surface, the detection device has the posture and shape of the first surface. The charged particle device according to any one of claims 96 to 134, wherein the position changing device changes the positional relationship while detecting either one and one of the posture and the shape of the second surface.
One of the postures and shapes of the first surface and the posture of the second surface before the relative positions of the irradiation device and the object change along at least one of the first surface and the second surface. And equipped with a detection device to detect either one of the shapes
The position changing device is the first by the detection device during at least a part of a period in which the relative position between the irradiation device and the object is changing along at least one of the first surface and the second surface. According to any one of claims 96 to 135, the positional relationship is changed based on the detection result of either one of the attitudes and shapes of the surfaces and the detection result of either one of the attitudes and shapes of the second surface. The charged particle device described.
The charged particle apparatus according to any one of claims 96 to 136, wherein at least a part of the surface of the object faces at least a part of the vacuum region.
The charged particle apparatus according to any one of claims 96 to 137, wherein at least a part of the surface of the object is covered with at least a part of the vacuum region.
The charged particle according to any one of claims 96 to 138, wherein a part of the surface of the object faces the vacuum region and the other part of the surface of the object faces the atmospheric pressure region. apparatus.
The charged particle apparatus according to any one of claims 96 to 139, wherein the surface of the object includes at least a part of the surface of the sample.
The charged particle apparatus according to claim 140, wherein the second surface includes an opposing surface of the surface of the sample facing the first surface.
The charged particle apparatus according to any one of claims 96 to 139, wherein the surface of the object includes at least a part of the surface of a holding member that holds the sample.
The charged particle apparatus according to claim 142, wherein the second surface includes a holding surface for holding the sample among the holding members.
The charged particle apparatus according to claim 142 or 143, wherein the second surface includes a peripheral surface of the holding member located at a position different from the holding surface along the holding surface for holding the sample.
The charged particle apparatus according to any one of claims 96 to 139, wherein the surface of the object includes at least a part of the surface of the member arranged between the sample and the vacuum forming member.
The charged particle apparatus according to claim 145, wherein the second surface includes an opposing surface facing the first surface among the surfaces of a member arranged between the sample and the vacuum forming member.
The irradiation device irradiates the sample held by the holding member with the charged particles.
Before the holding member holds the sample, (i) the object is the holding member, and (ii) the second surface includes a holding surface of the holding member that holds the sample. iii) The detection device detects one of the posture and shape of the first surface and one of the posture and shape of the holding surface, and (iv) the position change device is the first surface. Based on the detection result of either one of the posture and the shape of the holding surface and the detection result of either the posture and the shape of the holding surface, the positional relationship is changed.
After the holding member holds the sample, (i) the object is the sample, and (ii) the second surface includes an opposing surface of the surface of the sample that faces the first surface. , (Iii) The detection device detects one of the posture and shape of the first surface and one of the posture and shape of the facing surface, and (iv) the position change device is the first. According to any one of claims 96 to 139, the positional relationship is changed based on the detection result of either one of the posture and the shape of one surface and the detection result of either one of the attitude and the shape of the facing surface. The charged particle device described.
The position changing device has one of the posture and shape of the first surface and the posture and shape of the target surface at the timing when the charged particles are irradiated on the target surface which is a part of the second surface. The charged particle apparatus according to any one of claims 96 to 147, which changes the positional relationship based on any one of the above.
The irradiation device irradiates the charged particles so that the irradiation positions of the charged particles move relatively on the second surface.
The charged particle apparatus according to claim 148, wherein the position of the target surface on the second surface changes according to the relative movement of the irradiation position of the charged particles with respect to the second surface.
A detection device that detects either one of the posture and shape of the target surface and also detects one of the posture and shape of the inclusion surface that is a part of the second surface and includes the target surface. The charged particle apparatus according to claim 148 or 149.
The charged particle device according to claim 150, wherein the detection device uses the same detector to detect one of the postures and shapes of the target surface and the inclusion surface.
The claim includes a third detector capable of detecting either one of the posture and the shape of the target surface and a fourth detector capable of detecting one of the posture and the shape of the inclusion surface. The charged particle apparatus according to 150 or 151.
The charged particle device according to claim 152, wherein the third detector is arranged inside the fourth detector in the radial direction of the axis along the charged particles.
The charged particle device according to any one of claims 96 to 153, wherein the position changing device includes a first moving device capable of moving the irradiation device.
The charged particle device according to any one of claims 96 to 154, wherein the position changing device includes a second moving device capable of moving the object.
The charged particle device according to any one of claims 96 to 155, wherein the injection port is connected to an exhaust device.
The charged particle apparatus according to claim 156, wherein the other end of the first pipeline on the vacuum region side is formed around the injection port on the first surface.
The charged particle apparatus according to claim 157, wherein the degree of vacuum at the outlet is higher than the degree of vacuum at the other end.
The charged particle device according to any one of claims 1 to 158, wherein the vacuum forming member is a differential exhaust type vacuum forming member.
The charged particle device according to any one of claims 1 to 159, wherein the charged particles irradiated by the irradiation device irradiate the sample through the vacuum region.
A charged particle detection device for detecting charged particles emitted from the sample irradiated with the charged particles is provided.
The charged particle device according to any one of claims 1 to 160, which acquires information on the sample based on the detection result of the charged particle detection device.
The exhaust device to which the vacuum forming member is connected includes a first exhaust device and a second exhaust device.
The second exhaust device exhausts a region having a lower degree of vacuum than the vacuum formed by the first exhaust device, and is used as an auxiliary pump of the first exhaust device according to any one of claims 1 to 161. The charged particle device according to paragraph 1.
Using a vacuum forming member having a first pipeline and a first surface that can be connected to the exhaust device, the gas in the space of the object in contact with the second surface that can face the first surface is passed through the first pipeline. To form a vacuum region by discharging through
Discharging at least a part of the gas in the space around the vacuum region, which has a higher atmospheric pressure than the vacuum region, through the first pipeline.
Irradiating charged particles toward the sample from the injection port formed on the first surface, and
Irradiating the sample by passing at least a part of the vacuum region through the charged particles.
A method of irradiating charged particles, which comprises changing the positional relationship between the first surface and the second surface based on either the posture and the shape of the first surface.
A gas in a space having a first pipeline and a first surface that can be connected to an exhaust device and in contact with a second surface of an object that can face the first surface is discharged through the first pipeline. And the vacuum forming member that forms the vacuum region,
A position changing device for changing the positional relationship between the first surface and the second surface based on either the posture or the shape of the first surface is provided.
A vacuum forming apparatus in which at least a part of a gas in a space around the vacuum region having a higher atmospheric pressure than the vacuum region is discharged through the first pipeline of the vacuum forming member.
The vacuum forming apparatus according to claim 163 or 164, wherein the posture of the first surface includes information in the normal direction of the first surface.
The position change device according to any one of claims 163 to 165, which changes the positional relationship between the first surface and the second surface based on either the posture and the shape of the second surface. Vacuum forming device.
The vacuum forming apparatus according to claim 166, wherein the posture of the second surface includes information in the normal direction of the second surface.
The positional relationship between the first surface and the second surface is at least the distance between the first surface and the second surface and the relative relationship between the posture of the first surface and the posture of the second surface. The vacuum forming apparatus according to any one of claims 163 to 167, which includes one.
The vacuum according to claims 163 to 168, wherein the position changing device changes the positional relationship so that the first surface and the second surface approach parallel to each other as compared with before the positional relationship is changed. Forming device.
The vacuum forming device according to any one of claims 163 to 169, wherein the position changing device changes the positional relationship so that the first surface and the second surface are parallel to each other.
The vacuum forming device according to any one of claims 163 to 170, wherein the position changing device changes the positional relationship so as to prevent contact between the first surface and the second surface.
One of the postures and shapes of the first surface is such that the first surface and the third surface come into contact with a reference member having a third surface that can include at least a part of the first surface. The vacuum forming apparatus according to any one of claims 163 to 171, which is indirectly detected by contacting the vacuum forming member with the vacuum forming member and irradiating the third surface with a detection beam from the detection apparatus.
A storage device for storing information regarding either the posture or the shape of the first surface is provided.
Claims 163 to 172 change the positional relationship between the first surface and the second surface based on either the posture and the shape of the first surface stored in the storage device. The vacuum forming apparatus according to any one of the above.
The vacuum forming apparatus according to any one of claims 163 to 173, comprising a detecting apparatus for detecting either one of the posture and the shape of the first surface.
The vacuum forming device according to claim 174, wherein the detection device detects either one of the posture and the shape of the second surface.
The vacuum forming device according to claim 175, wherein the detection device detects one of the postures and shapes of the first surface and the second surface using the same detector.
The vacuum forming apparatus according to claim 176, wherein the detector is arranged at a first position fixed to the vacuum forming member.
The positional relationship between the detector and the vacuum forming member when detecting either one of the posture and shape of the first surface is the detection when detecting either one of the posture and shape of the second surface. The vacuum forming apparatus according to claim 176 or 177, which has the same positional relationship with respect to the vacuum forming member of the vessel.
The vacuum forming apparatus according to any one of claims 176 to 178, wherein the detector is arranged at a second position fixed to the object.
The positional relationship between the detector and the object when detecting either one of the posture and the shape of the first surface is the same as that of the detector when detecting either the posture and the shape of the second surface. The vacuum forming apparatus according to any one of claims 176 to 179, which has the same positional relationship with the object.
The vacuum forming apparatus according to any one of claims 176 to 180, wherein the detector irradiates the first surface with a detection beam to detect one of the posture and the shape of the first surface.
The vacuum forming apparatus according to any one of claims 176 to 181. The detector irradiates the second surface with a detection beam to detect one of the posture and the shape of the second surface.
The detector is in a state in which a reference member having a fourth surface capable of including at least a part of the first surface is in contact with the vacuum forming member so that the first surface and the fourth surface are in contact with each other. The vacuum forming apparatus according to any one of claims 176 to 182, wherein the fourth surface is irradiated with a detection beam to detect one of the posture and the shape of the first surface.
The vacuum forming apparatus according to claim 183, wherein each of the first surface and the fourth surface is a flat surface.
The reference member is a first reference member.
The detector has a fifth surface that can include at least a part of the second surface, and a second reference member different from the first reference member is the second surface and the fifth surface. The vacuum formation according to claim 183 or 184, wherein the fifth surface is irradiated with a detection beam to detect either the posture and the shape of the second surface in a state of being in contact with the object. apparatus.
The vacuum forming apparatus according to claim 185, wherein each of the second surface and the fifth surface is a flat surface.
The claim includes a first detector that detects one of the postures and shapes of the first surface, and a second detector that detects one of the postures and shapes of the second surface. The vacuum forming apparatus according to any one of 175 to 186.
One of the first and second detectors is arranged in a first position fixed to the vacuum forming member.
The vacuum forming apparatus according to claim 187, wherein the other of the first and second detectors is arranged at a second position fixed to the object.
The vacuum forming apparatus according to claim 187 or 188, wherein the first detector irradiates the first surface with a detection beam to detect either the posture or the shape of the first surface.
The vacuum forming apparatus according to any one of claims 187 to 189, wherein the second detector irradiates the second surface with a detection beam to detect one of the posture and the shape of the second surface.
In the first detector, a reference member having a fourth surface capable of including at least a part of the first surface contacts the vacuum forming member so that the first surface and the fourth surface come into contact with each other. The vacuum forming apparatus according to any one of claims 187 to 190, wherein the fourth surface is irradiated with a detection beam to detect one of the posture and the shape of the first surface.
The vacuum forming apparatus according to claim 191 in which each of the first surface and the fourth surface is a flat surface.
The reference member is a first reference member.
The second detector has a fifth surface that can include at least a part of the second surface, and a second reference member different from the first reference member is the second surface and the second surface. The 191 or 192 according to claim 191 or 192, in which the fifth surface is irradiated with a detection beam to detect either the posture or the shape of the second surface in a state of being in contact with the object so as to be in contact with the five surfaces. Vacuum forming device.
The vacuum forming apparatus according to claim 193, wherein each of the second surface and the fifth surface is a flat surface.
The first and second detectors irradiate the same sixth surface with a detection beam to further detect one of the posture and shape of the sixth surface.
After associating the detection result of one of the posture and the shape of the first surface with the detection result of one of the posture and the shape of the second surface based on the detection result of the sixth surface, the association is made. Any one of claims 187 to 194 that changes the positional relationship based on the detection result of either one of the posture and shape of the first surface and the detection result of either one of the posture and shape of the second surface. The vacuum forming apparatus according to one item.
The first and second detectors irradiate two different seventh surfaces having known positional relationships with a detection beam to further detect one of the posture and shape of the seventh surface.
After associating the detection result of one of the posture and the shape of the first surface with the detection result of one of the posture and the shape of the second surface based on the detection result of the seventh surface, the association is made. Any one of claims 187 to 195 that changes the positional relationship based on the detection result of either one of the posture and shape of the first surface and the detection result of either one of the posture and shape of the second surface. The vacuum forming apparatus according to one item.
The vacuum forming apparatus according to any one of claims 163 to 196, wherein an end portion of the first pipeline on the vacuum region side is formed on the first surface.
The end portion is a first end portion of the first pipeline on the vacuum region side, and a second end portion of the first pipeline on the vacuum region side is formed on the first surface. The vacuum forming apparatus according to claim 197.
The vacuum forming apparatus according to claim 198, wherein the degree of vacuum at the first end is higher than the degree of vacuum at the second end.
The vacuum forming apparatus according to any one of claims 163 to 199, wherein the vacuum forming apparatus is a differential exhaust type vacuum forming member.
Using a vacuum forming member having a first pipeline and a first surface that can be connected to the exhaust device, the gas in the space of the object in contact with the second surface that can face the first surface is passed through the first pipeline. To form a vacuum region by discharging through
Discharging at least a part of the gas in the space around the vacuum region, which has a higher atmospheric pressure than the vacuum region, through the first pipeline.
A method for forming a vacuum region, which comprises changing the positional relationship between the first surface and the second surface based on either the posture and the shape of the first surface.