TW201830451A - Apparatus of Plural Charged-Particle Beams - Google Patents

Abstract

A new multi-beam apparatus with a total FOV variable in size, orientation and incident angle, is proposed. The new apparatus provides more flexibility to speed the sample observation and enable more samples observable. More specifically, as a yield management tool to inspect and/or review defects on wafers/masks in semiconductor manufacturing industry, the new apparatus provide more possibilities to achieve a high throughput and detect more kinds of defects.

Description

Multi-charged particle beam device

The present invention relates to a device having a multi-charged particle beam, and more to an apparatus for utilizing multiple charged particle beams to simultaneously obtain images of a plurality of scanning regions. Thus, the apparatus provided by the present invention can be used to inspect and/or revisit wafers or reticle in the field of semiconductor fabrication in a high resolution and high throughput manner.

The following description and examples in this section are not a prior art that is recognized in this application.

In the process of manufacturing a semiconductor circuit wafer, pattern defects or unacceptable particles (for example, residues) inevitably appear on the surface of the wafer or the reticle, resulting in a large drop in yield. Therefore, defects or particles must be detected or re-examined with a yield management tool. In order to achieve ever-increasing performance of the wafer, smaller patterns and smaller key feature sizes have been employed. As such, due to the diffraction effect, traditional yield management tools that utilize beam are becoming increasingly incompetent and are being replaced by yield management tools that utilize particle beams. Compared to a photon beam, the electron beam has a shorter wavelength and therefore provides better spatial resolution. At present, the electron beam yield management tool employs the principle of a single electron beam of a scanning electron microscope (SEM), which is known to have a drawback in that the ability to process a sample cannot cope with mass production. Although increasing the beam current improves the yield, the Coulomb Effect causes a significant reduction in spatial resolution as the current increases.

In order to increase productivity, a better method is to use multiple electron beams, each of which has a small current. The multiple electron beams form a plurality of probe spots on the observation surface of the sample to be tested, or simply referred to as a probe spot array. The plurality of detection points can simultaneously and simultaneously scan a plurality of small scanning areas in a large observation area on the surface of the sample. The electrons of each probe point hit the surface of the sample and thereby generate secondary electrons. Secondary electrons contain slow secondary electrons (energy less than 50 eV) and backscattered electrons (whose energy is close to the landing energy of the electron). Secondary electrons reflected from a plurality of small scanning regions can be collected by a plurality of electronic detectors, respectively, at the same time. Thus, multi-electron beam scanning can more quickly obtain images of large viewing areas with multiple small scanning areas compared to scanning using a single electron beam.

Multiple electron beams can be derived from multiple electron sources, respectively, or from a single electron source. For a multi-electron source, a plurality of electron beams are usually focused and scanned through a plurality of electron columns, and a plurality of small scanning regions are scanned, and secondary electrons generated from each of the small scanning regions are disposed corresponding to each other. Detected by an electronic detector in the electron cavity. Therefore, such devices are often referred to as multi-electron cavity devices or devices. On the surface of the sample, the spacing of the multiple electron beams from each other is on the order of several or tens of millimeters (mm).

For a single electron source, a single electron source is typically converted to a plurality of sub-sources using an electron source conversion unit. The electron source conversion unit includes a beamlet-limit or beamlet-forming tool or method having a plurality of beam limiting openings, and a multi-electron optical element for image formation Tool or method. The plurality of beam limiting openings respectively divide a primary-electron beam generated by a single electron source into a plurality of sub-beams or beams. The plurality of electro-optical elements affect the plurality of beams to form a plurality of first parallel (virtual or real) images of the single electron source, respectively. Each first image is an intersection of a beam and can be viewed as a secondary electron source that emits a corresponding beam. In order to increase the amount of beam, the spacing between the beams is a micro meter level. In addition, a one-shot imaging system and a skew scanning unit disposed within the electron cavity are used to project a plurality of first parallel images and to scan the plurality of small scan regions, respectively. The secondary electrons generated from the scanning are directed by a beam splitter to a secondary projection imaging system, and then the second projection imaging system focuses the secondary electrons by a plurality of electronic detection devices disposed in a single electron cavity. Detection by a detection unit. The plurality of detecting units may be a plurality of electronic detectors disposed side by side or a plurality of pixels of an electronic detector. Due to the above features, the above devices are often referred to as multi-electron beam devices.

A tool or method for beam limiting is typically a conductive plate having a plurality of perforations, wherein the plurality of perforations are used as a plurality of beam confinement openings. And the work or method of image formation, each electron optical component is to focus a beam to form a real image (such as US Patent No. 7,244,949 and the fourth application in the related application), or The beam is deflected to form a virtual image (e.g., U.S. Patent No. 7,244,949, the entire disclosure of which is incorporated herein by reference). Figures 1 and 2 show two examples of the fifth related application in this case. For clarity of presentation, only three beams are shown in the figure, and the skew scanning unit, beam splitter, secondary projection imaging system, and electronic detection device are omitted.

As shown in FIG. 1A, the primary electron beam 102 generated by the electron source 101 is focused by the collecting lens 110 and incident on the electron source converting unit 120. The electron source conversion unit 120 includes a pre-beam bending tool 123 having three pre-curved micro-deflectors (123_1, 123_2, 123_3), and a beam limiting tool 121 of three beam limiting openings (121_1, 121_2, 121_3), And an image forming tool 122 of three electro-optical elements (122_1, 122_2, 122_3). The three pre-curved micro deflectors (123_1, 123_2, 123_3) respectively deflect the three beams (102_1, 102_2, 102_3) to be orthogonal to the three beam limiting openings (121_1, 121_2, 121_3), respectively. . And each of the beam limiting openings (121_1, 121_2, 121_3) acts as a beam limiting opening to limit the current of the corresponding beam. The three electron optical elements (122_1, 122_2, 122_3) respectively deflect the three beams (102_1, 102_2, 102_3) toward the optical axis 100_1 and form three first virtual images of the electron source 101, that is, Each beam has a virtual crossover. The primary projection imaging system is constructed of an objective lens 131 that focuses the three deflected beams 102_1~3 onto the surface 7 of the sample 8, i.e., projects three first virtual images onto the surface 7. Therefore, the three beams 102_1~3 form three detection points (102_1s, 102_2s, 102_3s) on the surface 7. The current of the probe points (102_1s, 102_2s, 102_3s) can be changed by adjusting the power of the condenser lens 110. As shown in FIG. 1B, the movable condensing lens 210 focuses the primary electron beam 102 so that its normal is incident on the beam limiting tool 121 of the electron source converting unit 220, so that the pre-beam bending tool 123 as shown in FIG. 1A is not required. . Therefore, the currents of the probe points (102_1s, 102_2s, 102_3s) can be changed by adjusting the magnification and position of the movable concentrating lens 210. As shown in FIGS. 1A and 1B, the beam (102_1, 102_2, 102_3) impacts the landing energy of the surface 7 of the sample, the magnitude of which can be varied by adjusting the potential of the electron source 101 and/or the sample surface 7.

In a multi-electron beam device, each beam scans a sub-FOV (field of view) of the sample surface 7, and the total field of view is the sum of the sub-fields of all beams. Each secondary field of view is equal to or smaller than the beam spacing of the sample surface (Ps, Figure 1A). In order to increase productivity, each sub-field of view preferably has its imaging resolution selected such that its beam spacing is altered to maintain the subfield of view. In the case of high image resolution, smaller sized pixels are used and a smaller secondary field of view is required to avoid excessive number of pixels. If it is low image resolution, a larger size pixel is used and a larger secondary field of view is required to increase productivity. Figure 2A shows an example of low image resolution. As indicated by the broken line in Fig. 2A, if the detection points 102_2s and 102_3s can be moved to the right and left, respectively, the beam pitch Ps will change from P1 to P2, and the total field of view will increase from 3 × P1 to 3 × P2, resulting in increased productivity. . Therefore, making the beam pitch Ps selectable will be a more preferable function.

The continuous scan mode (a continuous movement of a sample such that it is orthogonal to a scan direction of a primary electron beam) is a conventional method that increases the productivity of conventional single electron beam devices. If this method is used in a multi-electron beam device, it is preferable to match the total field of view or the orientation of the array of detection points to the direction of movement of the platform. It is well known that if there is a magnetic lens in a projection imaging system, its magnetic field will rotate the beam as well as the total field of view. Since the magnetic field changes with observation conditions, such as landing energy and currents of multiple beams, the angle of rotation of the total field of view also changes. Fig. 2B shows an example in which the objective lens 131 of Fig. 1A is replaced by a magnetic or electromagnetic composite lens. For example, when the landing energy of the beams 102_1~102­_3 is changed from 1 keV to 2 keV, the probe points 102_2S and 102_3S are rotated by an angle θ about the optical axis 100_1 indicated by a broken line. The change in the orientation of the total field of view will affect the characteristics of the continuous scan mode. Keeping the orientation of the array of probe points consistent or making them selectable provides more flexibility to improve productivity and is therefore a more preferred feature.

For some samples, the orientation of the pattern on the sample may be specifically matched to the orientation of the array of probe points. The orientation of the array of probe points is made selectable to compensate for mismatches due to limited grounding accuracy, thereby avoiding the time it takes to impact again, which increases productivity. Furthermore, in order to effectively observe some of the patterns of a sample, multiple beams may need to be struck on the surface of the sample at a particular angle of incidence. If the angle of incidence angle is made selectable, the observability of the various samples will be provided, so this would be a more preferred function.

The present invention will provide a method or apparatus for carrying out the desired functions described above, practiced in the manner of multiple electron beam devices, particularly those related to the present application, and as a yield management tool in the field of semiconductor fabrication.

The following are the applications related to this case:

(1) U.S. Patent Application, Publication No. US 6,943,349, Application Date, April 2001, inventor Pavel Adanec et al.

(2) US Patent Application, Bulletin No. US 7,244,949, filing date March 2006, inventor Ranier Knippelmeyer et al.

(3) US Patent Application, Application No. 15/065,342, filing date March 2016, inventor Weiming Ren et al.

(4) US Patent Application, Application No. 15/078,369, filing date March 2016, inventor Weiming Ren et al.

(5) US patent application, application number 15/150,858, application date May 2016, inventor Xuedong Liu et al.

(6) US patent application, application number 15/213,781, filing date July 2016, inventor Shuai Li et al.

(7) US Patent Application, Application No. 15/216,258, filing date July 2016, inventor Weiming Ren et al.

(8) US Patent Application, Application No. 15/365,145, filing date November 2016, inventor Weiming Ren et al.

It is an object of the present invention to provide a novel multi-charged particle beam apparatus that observes a sample with higher analysis rate and productivity and increases the elasticity of changing observation conditions. Based on the conventional multi-electron beam apparatus proposed in the related application of the present application, the present invention provides several methods for accomplishing a novel multi-charged particle beam apparatus having a variable field of view. This new multi-charged particle beam device has features such as variable size, orientation, and angle of incidence. As a result, the novel multi-charged particle beam device provides more flexibility to accelerate sample observation and make more samples observable. More particularly, the novel multi-charged particle beam device can be used as a yield management tool in the semiconductor manufacturing industry to detect and/or re-inspect wafers/masks, and the novel multi-charged particle beam device will likely Achieve high productivity and detect more types of defects.

According to the above object, an embodiment of the present invention provides a multi-charged particle beam device for observing a surface of a sample, comprising an electron source, a collecting lens, an electron source converting unit, an objective lens, and a skew scanning unit. , a sample stage, a beam splitter, a secondary projection imaging system, and an electronic detection device. The concentrating lens is located below the electron source. The electron source conversion unit is located below the concentrating lens. The object is located below the electron source conversion unit. The skew scanning unit is located below the electron source conversion unit. The sample stage is located below the objective lens. The beam splitter is located below the electron source conversion unit. The electronic detection device has a plurality of detection elements. The electron source, the collecting lens, and the objective lens are arranged with an optical axis of the multi-charged particle beam device, the sample stage supporting the sample, the surface of the sample facing the objective lens. The electron source conversion unit includes a beam limiting tool having a plurality of beam limiting openings, and an image forming tool having a plurality of electron optical elements movable along the optical axis. The electron source generates a primary electron beam along the optical axis, the focusing lens focusing the primary electron beam. A plurality of beams of the primary electron beam respectively pass through the plurality of beam confinement openings and are deflected by the electron optical elements toward the optical axis to form a plurality of virtual images of the electron source, respectively. The objective lens focuses the plurality of beams on the surface of the sample to form a plurality of detection points on the surface, the deflection scanning unit deflecting the plurality of beams to be within an observation area of the surface The plurality of detection points are scanned in a plurality of scan areas. The plurality of detection points respectively generate a plurality of secondary electron beams from the plurality of scanning regions, the secondary electron beams being guided by the beam splitter to the secondary projection imaging system, the secondary projection imaging system focusing and maintaining The plurality of secondary electron beams are respectively detected by the plurality of detecting elements, and each of the detecting elements thus provides an image signal corresponding to the scanning area.

In one embodiment, the skew angles of the plurality of beams due to the plurality of electron optical elements in the multi-charged particle beam device are respectively set to reduce off-axis deviation of the plurality of detection points. By moving the image forming tool along the optical axis, the spacing between the plurality of probe points can be adjusted together. The objective lens comprises a magnetic lens and an electrostatic lens. The orientation of the plurality of detection points is selectable, and the orientation of the detection point is changed by changing the zoom magnification of the magnetic lens and the electrostatic lens.

In one embodiment, the skew angle in the multi-charged particle beam device ensures that a plurality of beams land on the surface in a direction orthogonal or substantially orthogonal to the surface. The skew angle ensures that a plurality of beams land on the surface at a particular angle. The skew scanning unit is located on a front focusing surface of the objective lens. The skew scanning unit tilts the plurality of beams such that each beam landed on the surface at the same or substantially the same landing angle. The multi-charged particle beam device can also include a beam tilt deflector between the electron source conversion unit and a front focusing surface of the objective lens. The beam tilt deflector tilts the plurality of beams such that each beam land on the surface at the same or substantially the same landing angle.

According to the above object, an embodiment of the present invention provides a multi-charged particle beam device for observing a surface of a sample, comprising an electron source, a collecting lens, an electron source converting unit, an objective lens, and a skew scanning unit. , a sample stage, a beam splitter, a secondary projection imaging system, and an electronic detection device. The electron source conversion unit is located below the concentrating lens. The objective lens is located below the electron source conversion unit. The skew scanning unit is located below the electron source conversion unit. The sample stage is located below the objective lens. The beam splitter is located below the electron source conversion unit. The electronic detection device has a plurality of detection elements. The electron source, the collecting lens, and the objective lens are arranged with an optical axis of the multi-charged particle beam device, the sample stage supporting the sample, the surface of the sample facing the objective lens. The electron source conversion unit includes a beam limiting tool having a plurality of beam limiting openings, a first image forming tool having a plurality of first electron optical elements, and a second image having a plurality of second electron optical elements Forming a tool, the second image forming tool is located below the first image forming tool and moves along a radial direction, and the first image forming tool or the second image forming tool is used as an active image forming tool. The electron source generates a primary electron beam along the optical axis, the focusing lens focusing the primary electron beam. A plurality of beams of the primary electron beam respectively pass through the plurality of beam confinement openings and are deflected by the electron optical elements toward the optical axis to form a plurality of virtual images of the electron source, respectively. The objective lens focuses the plurality of beams on the surface of the sample to form a plurality of detection points on the surface, the deflection scanning unit deflecting the plurality of beams to be within an observation area of the surface The plurality of detection points are scanned in a plurality of scan areas. The plurality of detection points respectively generate a plurality of secondary electron beams from the plurality of scanning regions, the secondary electron beams being guided by the beam splitter to the secondary projection imaging system, the secondary projection imaging system focusing and maintaining The plurality of secondary electron beams are respectively detected by the plurality of detecting elements, and each of the detecting elements thus provides an image signal corresponding to the scanning area.

In one embodiment, the skew angles of the plurality of beams due to the active image forming tool in the multi-charged particle beam device are respectively set to reduce the off-axis deviation of the plurality of detection points. By switching between the first image forming tool and the second shadow forming tool into the active image forming tool, the spacing between the plurality of detecting points can be adjusted together. When the first image forming tool is selected, the second image forming tool is removed to avoid blocking the plurality of beams. The objective lens comprises a magnetic lens and an electrostatic lens. By changing the zoom ratio of the magnetic lens and the electrostatic lens, the orientation of the plurality of detection points can be changed.

In one embodiment, the skew angle in the multi-charged particle beam device ensures that a plurality of beams land on the surface in a direction orthogonal or substantially orthogonal to the surface. The skew angle ensures that a plurality of beams land on the surface at a particular angle. The skew scanning unit is located on a front focusing surface of the objective lens. The skew scanning unit tilts the plurality of beams such that each beam landed on the surface at the same or substantially the same landing angle. The multi-charged particle beam device can also include a beam tilt deflector between the electron source conversion unit and a front focusing surface of the objective lens. The beam tilt deflector tilts the plurality of beams such that each beam land on the surface at the same or substantially the same landing angle.

According to the above object, an embodiment of the present invention provides a multi-charged particle beam device for observing a surface of a sample, including an electron source, a collecting lens, an electron source converting unit, an objective lens, and a skew scanning unit. A sample stage, a beam splitter, a secondary projection imaging system, and an electronic detection device. The collecting lens is located below the electron source. The electron source conversion unit is located below the concentrating lens. The objective lens is located below the electron source conversion unit. The skew scanning unit is located below the electron source conversion unit. The sample stage is located below the objective lens. The beam splitter is located below the electron source conversion unit. The electronic detection device has a plurality of detection elements. The electron source, the collecting lens, and the objective lens are arranged with an optical axis of the multi-charged particle beam device, a first principle plane of the objective lens is movable along the optical axis, and the sample stage supports the sample, the sample The surface faces the objective lens. The electron source conversion unit includes a beam limiting tool having a plurality of beam limiting openings, and an image forming tool having a plurality of electron optical elements. The electron source generates a primary electron beam along the optical axis, the focusing lens focusing the primary electron beam. A plurality of beams of the primary electron beam respectively pass through the plurality of beam confinement openings and are deflected by the electron optical elements toward the optical axis to form a plurality of virtual images of the electron source, respectively. The objective lens focuses the plurality of beams on the surface of the sample to form a plurality of detection points on the surface, the deflection scanning unit deflecting the plurality of beams to be within an observation area of the surface The plurality of detection points are scanned in a plurality of scan areas. The plurality of detection points respectively generate a plurality of secondary electron beams from the plurality of scanning regions, the secondary electron beams being guided by the beam splitter to the secondary projection imaging system, the secondary projection imaging system focusing and maintaining The plurality of secondary electron beams are respectively detected by the plurality of detecting elements, and each of the detecting elements thus provides an image signal corresponding to the scanning area.

In one embodiment, the skew angles of the plurality of beams due to the plurality of electron optical elements in the multi-charged particle beam device are respectively set to reduce off-axis deviation of the plurality of detection points. By moving the first principle plane along the optical axis, the spacing between the plurality of probe points can be adjusted together.

In one embodiment, the skew angle in the multi-charged particle beam device ensures that a plurality of beams land on the surface in a direction orthogonal or substantially orthogonal to the surface. The skew angle ensures that a plurality of beams land on the surface at a particular angle. The skew scanning unit is located on a front focusing surface of the objective lens. The skew scanning unit tilts the plurality of beams such that each beam landed on the surface at the same or substantially the same landing angle. The multi-charged particle beam device can also include a beam tilt deflector between the electron source conversion unit and a front focusing surface of the objective lens. The beam tilt deflector tilts the plurality of beams such that each beam land on the surface at the same or substantially the same landing angle. The objective lens comprises a magnetic lens and an electrostatic lens. The electrostatic lens contains a field of control electrodes and a field of moving electrodes and produces an electrostatic field. The potential of the field control electrode is set to control the electrostatic field on the surface to ensure that the surface does not experience electrical breakdown. The potential of the field moving electrode is set to move the electrostatic field to move the first principle plane. The orientation of the plurality of detection points can be changed by changing the potential of the field electrode and/or the field moving electrode. The multi-charged particle beam device further includes an upper magnetic lens positioned above the lower magnetic lens. The first principle plane can be moved by changing the zoom magnification ratio of the upper magnetic lens and the lower magnetic lens. By setting the polarities of the upper and lower magnetic lenses, the orientation of the plurality of detection points can be changed.

According to the above object, an embodiment of the present invention provides a multi-charged particle beam device for observing a surface of a sample, including an electron source, a collecting lens, an electron source converting unit, a conversion lens, a field lens, and an objective lens. a skew scanning unit, a sample stage, a beam splitter, a secondary projection imaging system, and an electronic detection device. The electron source conversion unit is located below the concentrating lens. The conversion lens is located below the electron source conversion unit. The field lens is located below the conversion lens. The objective lens is located below the field lens. The skew scanning unit is located below the electron source conversion unit. The sample stage is located below the objective lens. The beam splitter is located below the electron source conversion unit. The electronic detection device has a plurality of detection elements. The electron source, the concentrating lens, the conversion lens, the field lens, and the objective lens are arranged with an optical axis of the multi-charged particle beam device, the sample stage supporting the sample, the surface of the sample facing the objective lens. The electron source conversion unit includes a beam limiting tool having a plurality of beam limiting openings, and an image forming tool having a plurality of electron optical elements. The electron source generates a primary electron beam along the optical axis, the focusing lens focusing the primary electron beam. The plurality of beams of the primary electron beam respectively pass through the plurality of beam confinement openings and are deflected by the electron optical elements toward the optical axis to form a plurality of first virtual images of the electron source, respectively. The conversion lens images the plurality of first virtual images on an intermediate image plane, so that a plurality of second real images are formed on the intermediate image plane, the field lens is located on the intermediate image plane, and the plurality of beams are Bending, the lens imaging the plurality of second real images on the surface of the sample to form a plurality of detection points on the surface, the skew scanning unit deflecting the plurality of beams to observe an observation on the surface The plurality of detection points are scanned in a plurality of scanning areas in the area. The plurality of detection points respectively generate a plurality of secondary electron beams from the plurality of scanning regions, the secondary electron beams being guided by the beam splitter to the secondary projection imaging system, the secondary projection imaging system focusing and maintaining the The plurality of secondary electron beams are respectively detected by the plurality of detecting elements, and each of the detecting elements thus provides an image signal corresponding to the scanning area.

In one embodiment, the bending angles of the plurality of beams due to the field lens in the multi-charged particle beam device are respectively set to reduce the off-axis deviation of the plurality of detection points. The skew angles of the plurality of beams due to the plurality of optical electronic components are respectively set to adjust the spacing between the plurality of probe points. The objective lens includes a first magnetic lens and a first electrostatic lens. The orientation of the plurality of detection points can be changed by changing the zoom magnification ratio of the first magnetic lens and the first electrostatic lens. The field lens includes a third magnetic lens and a third electrostatic lens. The orientation of the plurality of detection points can be changed by changing the zoom magnification ratio of the third magnetic lens and the third electrostatic lens.

In one embodiment, the skew angle and the bend angle of the plurality of beams due to the plurality of optical elements in the multi-charged particle beam device ensure that the plurality of beams are orthogonal or substantially orthogonal to the surface. The direction is landing on the surface. The skew angles and bend angles of the plurality of beams due to the plurality of light elements ensure that the plurality of beams land on the surface at a particular angle. The skew scanning unit is located on a front focusing surface of the objective lens. The skew scanning unit tilts the plurality of beams such that each beam landed on the surface at the same or substantially the same landing angle. The multi-charged particle beam device can also include a beam tilt deflector between the electron source conversion unit and a front focusing surface of the objective lens. The beam tilt deflector tilts the plurality of beams such that each beam land on the surface at the same or substantially the same landing angle.

According to the above object, an embodiment of the present invention provides a method for configuring a multi-charged particle beam device for observing a surface of a sample, comprising the steps of: configuring an image forming tool of an electron source conversion unit, which can be along Moving an optical axis; forming a plurality of virtual images of an electron source by the image forming tool; imaging a plurality of virtual images on the surface by an objective lens and forming a plurality of detecting points on the surface; and moving the image forming tool To change the spacing between the plurality of probe points.

According to the above object, an embodiment of the present invention provides a method for configuring a multi-charged particle beam device for observing a surface of a sample, comprising the steps of: configuring a first image forming tool and a second image forming tool. An electron source conversion unit, wherein the distance between the second image forming tool and an electron source is longer than a distance between the first image forming tool and the electron source, and the second image forming tool can be along the multi-charged particle beam device Radial movement; using the first image forming tool or the second image forming tool as an active image forming tool, wherein when the first image forming tool is used, the second image forming tool is removed; The forming tool respectively forms a plurality of virtual images of the electron source; imaging the plurality of virtual images on the surface by an objective lens and forming a plurality of detecting points on the surface; and changing the active image forming tool to the first image forming tool Or the second image forming tool to change the spacing between the plurality of detection points.

According to the above object, an embodiment of the present invention provides a method for configuring a multi-charged particle beam device for observing a surface of a sample, comprising the steps of: configuring an objective lens having a first principle plane, the objective lens being along An optical axis movement of the multi-charged particle beam device; forming, by an image forming tool of an electron source conversion unit, a plurality of virtual images of an electron source; and imaging the plurality of virtual images on the surface by the objective lens and on the surface Forming a plurality of probe points; and moving the first principle plane to change a spacing between the plurality of probe points.

According to the above object, an embodiment of the present invention provides a method for configuring a multi-charged particle beam device for observing a surface of a sample, comprising the steps of: arranging a magnetic lens and a magnetic lens in the multi-charged particle beam device; An objective lens of an electrostatic lens; an image forming tool of an electron source converting unit respectively forming a plurality of virtual images of an electron source; imaging the plurality of virtual images on the surface with the objective lens and forming a plurality of detecting points on the surface; And changing a ratio of the lower magnetic lens and the zoom magnification of the electrostatic lens to select an orientation of the plurality of detection points.

In one embodiment, the method further includes an upper magnetic lens disposed on the objective lens, the upper magnetic lens being away from the surface than the lower magnetic lens. In one embodiment, the method further includes changing the polarity of the upper and lower magnetic lenses to change the orientation of the probe points.

According to the above object, an embodiment of the present invention provides a method for configuring a multi-charged particle beam device for observing a surface of a sample, comprising the steps of: using an image processing tool of an electron source conversion unit to connect an electron source The plurality of beams are deflected to form a plurality of first virtual images of the electron source; the plurality of first virtual images are imaged on the surface by an objective lens and a plurality of probe points are formed on the surface; and The skew angle of the plurality of beams caused by the image processing tool causes the plurality of beams to land on the surface at the same or substantially the same landing angle.

In one embodiment, the method further includes the step of varying the landing angle with the same amount of change by varying the skew angle. In one embodiment, the method further includes the step of utilizing a tilt scanning unit that tilts the plurality of beams to change the landing angle by the same amount of change. In one embodiment, the method further includes the step of utilizing a beam tilt deflector that tilts the plurality of beams to change the landing angle of the plurality of beams by the same amount of change.

According to the above object, an embodiment of the present invention provides a method for configuring a multi-charged particle beam device for observing a surface of a sample, comprising the steps of: using an image processing tool of an electron source conversion unit to connect an electron source The plurality of beams are deflected to form a plurality of first virtual images of the electron source; the plurality of first virtual images are imaged by a conversion lens on an intermediate image plane and a plurality of second real images are formed; A field lens on the intermediate image plane multiplies the plurality of beams; and an objective lens forms a plurality of second real images on the surface and forms a plurality of detection points on the surface.

In one embodiment, the method further includes the step of changing the skew angle of the plurality of beams due to the image forming tool to change the pitch of the plurality of probe points. In one embodiment, the method further includes the step of varying a skew angle of the plurality of beams due to the image forming tool and a bending angle of the plurality of beams due to the field lens, such that the plurality of beams are identical or substantially The same landing angle landed on the surface. In one embodiment, the method further includes the step of varying the tilt angle to change the landing angle of the plurality of beams by the same amount of change. In one embodiment, the method further includes the step of deflecting the skew angles of the plurality of beams by an equal amount using a skew scanning unit. In one embodiment, the method further includes the step of deflecting the skew angles of the plurality of beams by an equal amount using a beam tilt deflector. In one embodiment, the method further includes the step of configuring an objective lens having a first magnetic lens and a first electrostatic lens. In one embodiment, the method further includes the step of changing a zoom ratio of the first magnetic lens and the first electrostatic lens to select an orientation of the plurality of detection points. In one embodiment, the method further includes a step of configuring a conversion lens having a second magnetic lens and a second electrostatic lens. In one embodiment, the method further includes the step of selecting an orientation of the plurality of detection points by changing a zoom magnification of the second magnetic lens and the second electrostatic lens. In one embodiment, the method further includes a step of configuring a field lens having a third magnetic lens and a third electrostatic lens. In one embodiment, the method further includes the step of selecting an orientation of the plurality of detection points by changing a zoom magnification of the third magnetic lens and the third electrostatic lens.

According to the above object, an embodiment of the invention provides a device comprising a particle source, a particle source conversion unit, and an objective lens. The particle source is used to provide a once charged particle beam. The particle source conversion unit divides the primary charged particle beam into a plurality of charged particle beams and forms a plurality of images of the particle source. The objective lens is located in the particle source conversion unit for projecting the plurality of images onto a surface of the sample. The spacing of the plurality of charged particle beams on the surface is adjusted by varying the tilt angle of the plurality of charged particle beams prior to entering the objective lens.

According to the above object, an embodiment of the invention provides a device comprising a particle source for providing a primary charged particle beam, and a beam for dividing the primary charged particle beam into a plurality of charged particle beams and forming the particle source. a plurality of image tools, an objective lens for projecting a plurality of images onto a surface of a sample, and an objective lens for forming a plurality of detection points on the surface, and a method for adjusting between the plurality of detection points on the surface Spacing tool.

In accordance with the above objects, embodiments of the present invention provide a method for observing a surface of a sample, comprising the steps of: providing a plurality of charged particle beams having a plurality of intersections; projecting the plurality of intersections on the surface of the sample to surface the sample Forming a plurality of detection points thereon; scanning the plurality of detection points on the surface of the sample; and changing a skew angle of the plurality of charged particle beams such that a spacing between the plurality of detection points is adjusted.

Other advantages and features of the present invention will become apparent from the following description of the embodiments illustrated herein.

The embodiments of the present invention will be described in detail below with reference to the drawings. By way of illustration, and not limitation, FIG. However, in other embodiments of the invention, other charged particle beams may also be used.

In the drawings, the size of elements may be exaggerated for clarity of presentation and the components and components may not be shown to scale. The same or similar component symbols in the drawings represent the same or similar components, and only the differences are described between the individual components.

Each and every embodiment of the present disclosure may be modified, changed, combined, exchanged, omitted, substituted, and changed equally, as long as it is not mutually exclusive, and belongs to the concept of the present invention. It is within the scope of the invention. The detailed description made in the embodiments of the present invention is illustrative and not restrictive.

In the present specification, "axial" refers to an electro-optical element such as a round lens or a multipole lens, or an optical axis direction of an imaging system or a device. "Radial" refers to the radial direction orthogonal to the optical axis. "On-axial" refers to the arrangement on the optical axis or on the optical axis. "Off-axial" means that it is not on the optical axis or is not aligned with the optical axis.

In the present specification, "an imaging system and an optical axis arrangement" means that all of the electro-optical elements, such as a round lens or a multipole lens, are arranged with the optical axis.

In the present specification, the X, Y, and X coordinates form a Cartesian coordinate, and the optical axis of the primary projection imaging system is at the Z coordinate, and the primary electron beam travels along the Z axis.

In the present specification, "primary electrons" refers to electrons emitted from an electron source and incident on a surface to be observed or to be inspected of a sample. "Secondary electrons" refers to electrons generated after a single electron is incident on the surface to be tested of the sample.

In the present specification, "pitch" refers to the distance between two adjacent beams or charged particle beams on a plane.

In the present specification, "the effective deflection plane of the deflector" refers to the plane where the total deflection function of the deflector can be equivalent to happen.

Based on some of the multi-electron beam devices mentioned in the related application of the present application, the present invention proposes a novel multi-charged particle beam device having a variable field of view (FOV). Wherein, the total field of view of the new multi-charged particle beam device can vary in size, orientation, and illumination angle. In order to clearly illustrate the method of the present invention, the present embodiment is exemplified by the multi-electron beam device of FIG. 1B. To simplify the description, the number of beams of the new multi-charged particle beam device is reduced to three, however the number of beams in other embodiments of the invention is not limited and may be any number. In addition, one of the three beams is on the shaft, but in other embodiments, the three beams may both be off-axis. Furthermore, elements not related to the present invention, such as skew scanning units and beam splitters, are not shown in the drawings and are not even mentioned in the specification.

In each of the conventional multi-electron beam devices, the image forming tool is used to deflect the plurality of beams toward the optical axis. The skew angle of the plurality of beams is set such that off-axis deviations of the plurality of probe points due to the objective lens are minimized. Thus, a plurality of deflected beams typically pass through or near the front focal point of the objective lens, that is, form an on-axis intersection on or near the front focal plane of the objective lens ( On-axis crossover). Therefore, the spacing between the plurality of probe points depends on the skew angle of the plurality of beams and the first or object focal length of the objective lens. Therefore, the pitch of the beam can be adjusted by changing the skew angle and/or the first focal length of the objective lens. For example, as shown in FIGS. 1A and 1B, the skew angles α2 and α3 of the two off-axis beams 102_2 and 102_3 may be set such that the off-axis deviations of the probe points 102_2s and 102_3s due to the objective lens 131 are minimized. Therefore, the beams 102_2 and 102_3 generally pass or approach the front focus of the objective lens 131, that is, form a crossover (Cover) with the optical axis at or near the front focusing surface of the objective lens 131. The spacing between the probe points 102_1s and 102_2s is determined by the skew angle α2 and the first focal length f of the objective lens 131, and can be simply expressed as . Similarly, the spacing between the probe points 102_1s and 102_3s is determined by the skew angle α3 and the first focal length f of the objective lens 131, and can be simply expressed as .

3A, 4A and 5A show an embodiment in which the multi-charged particle beam apparatus 300A, 400A, 500A adjusts the pitch of the probe points by changing the skew angle according to an embodiment of the present invention, and FIG. 6A shows a change of the 600A according to an embodiment of the present invention. An embodiment of adjusting the spacing of the probe points by a focal length. As shown in FIG. 3A, the electron source conversion unit 320 of the multi-charged particle beam device 300A includes a beam limiting tool 121 having three beam limiting openings 121_1, 121_2, 121_3. The electron source conversion unit 320 further includes a movable image forming tool 322 having three electron optical elements 322_1, 322_2, 322_3. The effective skew plane 322_0 of the movable image forming tool 322 can move within the variation range 322_or along the optical axis 300_1. When the effective skew plane 322_0 moves closer to the objective lens 131, the spacing between the probe points will become larger, and if it is reversed, it becomes smaller.

Figure 3B shows the path of the three beams 102_1, 102_2, 102_3 when the effective skew plane 322_0 is at position D1. The movable concentrating lens 210 collimates the primary electron beam 102 within the variation range 210_2 so as to be orthogonally incident into the electron source conversion unit 320. The beam limiting openings 121_1, 121_2, 121_3 divide the electron source into an on-axis beam 102_1 and two off-axis beams 102_2, 102_3. The two off-axis electro-optical elements 322_2, 322_3 deflect the beams 102_2, 102_3, respectively, toward the optical axis 300_1. The objective lens 131 focuses the three beams 102_1, 102_2, 102_3 on the surface 7 of the sample 8, thereby forming three detection points 102_1s, 102_1s, 102_3s, respectively. The skew angles α2 and α3 of the beams 102_2 and 102_3 are set, respectively, such that the off-axis deviation of the probe points 102_2 and 102_3 is minimized. Therefore, the beams 102_2 and 102_3 pass through the front focus of the objective lens 131, that is, on the optical axis 300_1 of the front focusing surface of the objective lens 131. The two spacings formed by the three detection points are approximately with Where f is the first focal length of the objective lens 131. The effective skew plane 322_0 of FIG. 3C is near the D2 position of the objective lens 131, not the D1 position. Therefore, the skew angles α2 and α3 are increased, and the interval between the detection points becomes large. As shown in Fig. 3C, the probe points 102_2s and 102_3s are moved outward from the original dotted line position of Fig. 3B.

As shown in FIG. 4A, the electron source conversion unit 420 of the multi-charged particle beam device 400A of the present embodiment further includes an image forming tool 124 having three electro-optical elements 124_1, 124_2, 124_3. . The image forming tool 124 is located below the image forming tool 122 and can move in the radial direction; therefore, the electron source conversion unit 420 has two modes of operation. As shown in FIG. 4B, in the first mode, the image forming tool 122 is three first virtual images for forming a single electron source 101, and the image forming tool 124 is moved out of the path of the beams 102_1, 102_2, 102_3. . As shown in FIG. 4B, in the second mode, the image forming tool 122 is turned off, and the image forming tool 124 is moved back to the original position to form the three first virtual images of the electron source 101. In the first mode, the skew angles α2 and α3 of the beams 102_2 and 102_3 are smaller than the skew angles α2 and α3 in the second mode. Therefore, the two probe points of the second mode will have a larger pitch than the two pitches of the first mode.

As shown in FIG. 5A, the multi-charged particle beam device 500A of the present embodiment further includes a conversion lens 533 and a field lens 534 between the electron source conversion unit 220 and the objective lens, as compared with the multi-electron beam device of FIG. 1B. Therefore, the conversion lens 533, the field lens 534, and the objective lens 131 constitute a primary projection imaging system. Figure 5B shows the path of beams 102_1, 102_2, 102_3. The movable condensing lens 210 collimates the primary electron beam 102 such that it is incident orthogonally into the electron source conversion unit 220. The beam limiting openings 121_1, 121_2, 121_3 divide the primary electron beam into an on-axis beam 102_1 and two off-axis beams 102_2 and 102_3. The two off-axis electro-optical elements 122_2 and 122_3 deflect the beams 102_2 and 102_3, respectively, toward the optical axis 500_1. Three first virtual images of a single electron source are then formed. The conversion lens 533 then focuses the three beams 102_1, 102_2, 102_3 on the intermediate image plane PP1, that is, three virtual first images are projected thereon. Therefore, the three second real images 102_1m, 102_2m, 102_3m of the single electron source 101 are formed. The field lens 534 is located on the intermediate image plane PP1 and diverts the off-axis beams 102_2 and 102_3 toward the optical axis 500_1 without affecting their focus condition. Thereafter, the objective lens 131 focuses the three beams 102_1, 102_2, 102_3 on the surface 7 of the sample 8, that is, three third real images are projected onto the surface 7. Next, on the surface 7 of the sample 8, three detection points 102_1s, 102_2s, 102_3s are formed, respectively.

As shown in FIG. 5B, the bending angles γ2 and γ3 of the beams 102_2 and 102_3 due to the field lens 534 are set, respectively, such that the off-axis deviation of the probe points 102_2s and 102_3s is minimized. The beams 102_2 and 102_3 thus pass through or approach the front focus of the objective lens 131, that is, form an intersection on the front focus plane of the objective lens 131 or the optical axis 500_1 near the focus plane. The detection points 102_1s and 102_2s are determined by the bending angle γ2 and the first focal length f of the objective lens 131, and can also be simply expressed as . Similarly, the detection points 102_1s and 102_3s are determined by the bending angle γ3 and the first focal length f of the objective lens 131, and can also be simply expressed as . The bending angles γ2 and γ3 change with the radial movement of the second real images 102_2m and 102_3m, and due to the electro-optical elements 122_2 and 122_3, the radial movements will follow the deflection angles α2 and α3 of the beams 102_2 and 102_3. change. Therefore, the two intervals between the probe points can be changed by adjusting the skew angles α1 and α2. As shown in Fig. 5C, the skew angles α1 and α2 are adjusted to be larger than the skew angles α1 and α2 of Fig. 5B, so that the two off-axis detection points 102_2s and 102_3s are moved from the original broken line position (Fig. 5B) to the present. The position shown in Fig. 5C causes the two pitches between the probe points to become large.

As shown in FIG. 6A, the first principal plane 631_2 of the objective lens 631 of the multi-charged particle beam device 600A is displaceable along the optical axis 600_1 within the variation range 631_2r. This axial displacement can be accomplished by mechanically moving the position of the objective lens 631 or by electronically altering the shape or position of the objective lens field. When the first principle plane approaches the surface 7 of the sample 8, the first focal length f becomes smaller and the first focal plane will move towards the surface 7. Further, when the first focus surface moves downward, the skew angle of the plurality of beams becomes small; therefore, the pitch between the plurality of probe points becomes small.

Figures 6B and 6C show the paths of the three beams when the first principle plane 631_2 is at positions D3 and D4, respectively. The D3 position is closer to the surface 7 of the sample 8 than the D4 position. Therefore, the first focal length f of FIG. 6B and the skew angles α2 and α3 of the beams 102_2 and 102_3 are smaller than the first focal length f of FIG. 6C and the skewed angles α2 and α3 of the beams 102_2 and 102_3. As shown in Fig. 6C, the probe points 102_2s and 102_3s are moved outward from the original dotted line position (Fig. 6B), and the pitch of the two probe points becomes larger as compared with Fig. 6B.

As shown in Fig. 1C, the objective lens 131-1 of the conventional multi-electron beam device is an electromagnetic composite lens. The objective lens comprises a magnetic lens and an electrostatic lens and operates in a delayed mode due to low geometric aberrations and low radiation damage to the sample (the landing energy of the electrons is lower than the energy of the electrons passing through the objective lens). The magnetic lens is composed of a coil 131_c1 and a yoke 131_y1 having magnetic poles 131_mp1 and 131_mp2. The electrostatic lens is composed of a magnetic pole 131_mp1, a field control electrode 131_e1, and a sample 8. The potential of the magnetic pole 131_mp1 is higher than the potential of the sample 8. The potential of the field control electrode 131_e1 is set to control the electric field of the surface 7 of the sample 8. The electric field can ensure that the surface 7 does not undergo electrical breakdown, reduces geometric aberrations of multiple detection points, controls partial charge of the surface 7 by reflecting secondary electrons, or increases the charge of secondary electrons. As shown in Fig. 1C, the shape of the magnetic field cannot be changed, and the shape of the electrostatic field can only be changed within a limited range. Thus, the conventional objective lens is almost incapable of being electrically controlled, that is, changing the potential of the electrode and/or changing the excitation current of the coil to move it.

According to the conventional objective lens 131-1 of Fig. 1C, the present invention Figs. 7A, 7B and 7C respectively provide three novel movable objective lenses 631-1, 631-2, 631-3. As shown in FIG. 7A, the objective lens 631-1 further includes an electrode 631-1_e2 interposed between the magnetic pole 131_mp1 and the field control electrode 131_e1, as compared with FIG. 1C. Therefore, the electrostatic lens is composed of the magnetic pole 131_mp1, the electrode 631-1_e2, the field control electrode 131_e1, and the sample 8. The shape of the electrostatic field of the electrostatic lens can be changed by adjusting the potential of the field control electrode 131_e1 and the potential of the electrode 631-1_e2. When the potential of the electrode 631-1_e2 is adjusted to be close to the potential of the magnetic pole 131_mp1, the electrostatic field is compressed toward the sample 8, which corresponds to moving the objective lens 631-1 toward the sample 8. Therefore, the electrode 631-1_e2 may also be referred to as a field moving electrode.

As shown in FIG. 7B, in contrast to FIG. 1C, the objective lens 631-2 further includes two electrodes 631-2_e2 and 631-2_e3 located in the recess of the yoke 131_y1 and on the field control electrode 131_e1. Therefore, the electrostatic lens is composed of the electrodes 631-2_e3 and 631-2_e2, the field control electrode 131_e1, and the sample 8. The potential of the electrode 631-2_e3 is higher than the potential of the sample 8, and may also be equal to the potential of the magnetic pole 131_mp1. The shape of the electrostatic field of the electrostatic lens can be changed by adjusting the potential of the electrode 131_e1 and the potential of the electrode 631-2_e2. Similar to the embodiment of Fig. 7A, in the embodiment of Fig. 7B, when the potential of the electrode 631-2_e2 is adjusted to be close to the potential of the electrode 631-1_e3, the electrostatic field is compressed toward the sample 8, which corresponds to moving the objective lens 631-2 toward the sample. 8. Therefore, the electrode 631-2_e2 may also be referred to as a field moving electrode. The magnetic lens of the embodiment of Fig. 7B can be placed closer to the sample 8 than the objective lens 631-1 of Fig. 7A, thus providing a deeper magnetic immersion of the sample 8, making the deviation smaller.

As shown in Fig. 7C, the objective lens 631-3 further includes a coil 631-3_c2 and a yoke 631-3_y2 located in the groove of the yoke 131_y1 and on the magnetic pole 131_mp1, as compared with Fig. 1C. Therefore, a lower magnetic lens, an upper magnetic lens, and an electrostatic lens are formed. Here, the lower magnetic lens generates a lower magnetic field by the coil 131_c1 transmitting through the low magnetic flux pitch G1 between the magnetic pole 131_mp1 of the yoke 131_1 and the magnetic pole 131_mp2. The upper magnetic lens generates a relatively upper magnetic field from the coil 631-3_c2 through the magnetic flux spacing G2 between the magnetic pole 131_mp1 and the magnetic poles 631-3_mp3 of the yoke 631-3_y2. The electrostatic lens is composed of a magnetic pole 131_mp1, a field control electrode 131_e1, and a sample 8. The distribution shape of the total magnetic field of the objective lens 631-3 changes with the combination of the above upper magnetic field and the lower magnetic field, so that the excitation ratio of the lower magnetic lens and the upper magnetic lens can be adjusted, or the current ratio of the coils 131_c1 and 631-3_c2 can be adjusted. And change. When the adjustment current is relatively high, the total magnetic field of the objective lens 631-3 is pressed toward the sample 8, which is equivalent to moving the objective lens 631-3 toward the sample 8. Two extreme examples are exemplified here. When the coil 131_c1 is closed and the coil 631-3_c2 is opened, the total magnetic field of the objective lens 631-3 is located above; in addition, when the coil 131_c1 is opened and the coil 631-3_c2 is closed, the total magnetic field of the objective lens 631-3 Located at the bottom. The embodiment of Figure 7C can be combined with the embodiment of Figures 7A and 7B in any way to practice more embodiments of the objective lens 631.

In the following embodiments, a method of rotating a array of detection points will be proposed, which can be used to eliminate azimuthal variations in the total field of view with respect to observation conditions, and/or to accurately match the orientation of the sample pattern and the orientation of the array of detection points. As previously described, the objective lens of the conventional multiple electron beam apparatus is an electromagnetic composite lens such as the objective lens 131-1 shown in Fig. 1C. Therefore, appropriately combining the zoom magnifications of the magnetic lens and the electrostatic lens allows the probe point to be rotated by an angle about the optical axis. For example, if the objective lens 131 in FIG. 1A is similar to the objective lens 131-1 in FIG. 1C, the field control electrode 131_e1 can be used to rotate the probe points 102_2s and 102_3s to an angle and control the electric field of the surface 7 of the sample 8. In order to maintain the electric field of surface 7 below an allowable value based on sample safety considerations, the potential of field control electrode 131_e1 can be adjusted over a particular range, such as between 3 kV and 5 kV relative to the sample. The focus magnification of the electrostatic lens varies with the potential of the field control electrode 131_e1, so the focus magnification of the magnetic lens must be changed to keep the plurality of beams focused on the surface 7 of the sample 8. The focus magnification of the magnetic lens changes, causing the rotation angles of the detection points 102_2S and 102_3S to change. Therefore, the rotation angles of the detection points 102_2s and 102_3s can be changed by adjusting the potential of the field control electrode 131_e1 within a specific range.

For the multi-charged particle beam devices 300A, 400A, and 500A of FIGS. 3A, 4A, and 5A, if the structure of the objective lens 131 is similar to the objective lens 131-1 of FIG. 1C, the angle of the array of detection points can be adjusted by this method. For the multi-charged particle beam device 600A of FIG. 6A, if the objective lens 631 has the structures of the objective lenses 631-1, 631-2, 631-3 as shown in FIGS. 7A to 7C, the field control electrodes 131_e1 and/or the corresponding field shifts The electrodes can be used to control the rotation of the array of probe points. With respect to the objective lens 631-3, the orientation of the detection point can be changed by changing the polarity of the magnetic field of the upper magnetic lens and the lower magnetic lens. For a magnetic lens, the rotation angle is related to the polarity of the magnetic field but is independent of the focus magnification, which is well known. When the polarities of the magnetic fields of the upper magnetic lens and the lower magnetic lens are the same, the upper magnetic lens and the lower magnetic lens rotate the array of detecting points in the same direction. When the polarities of the magnetic fields of the upper magnetic lens and the lower magnetic lens are opposite, the upper magnetic lens and the lower magnetic lens rotate the array of detecting points in opposite directions. Thus, for a desired focus magnification and corresponding position of the first principle plane, the objective lens 631-3 can produce two different arrays of probe point rotation directions.

As shown in Figure 5A, the conversion lens 533 and field lens 534 of the multi-charged particle beam 500A provide more possibilities for rotating the array of detection points. FIG. 8A shows a multi-charged particle beam device 510A according to another embodiment of the present invention, wherein the electromagnetic composite conversion lens 533-1 includes an electrostatic conversion lens 533_11 and a magnetic conversion lens 533_12. The magnetic field of the magnetic conversion lens 533_12 can be adjusted to change the rotation angle of the array of detection points; thus, the electrostatic field of the electrostatic conversion lens 533_11 can be changed to keep the three real images 102_1m, 102_2m, 102_3m on the intermediate image plane PP1. 8B shows a multi-charged particle beam device 520A in which an electromagnetic composite field lens 534-1 includes an electrostatic field lens 534_11 and a magnetic field lens 534_12, in accordance with another embodiment of the present invention. The magnetic field of the magnetic field lens 531_12 can be adjusted to change the angle of rotation of the array of detection points. The electrostatic field of the electrostatic field lens 534_11 can be varied to produce the desired bend angle for the plurality of beams.

In each of the foregoing embodiments, the plurality of beams are incident on the surface 7 of the sample 8 orthogonally or substantially orthogonally, that is, the angle of incidence or landing angle of the beam (the angle between the beam and the normal of the surface 7) Close to zero. In order to effectively observe some of the patterns of the sample 8, the angle of incidence is preferably slightly greater than zero. In order to ensure that multiple beams have the same performance, multiple beams must have the same angle of incidence. To achieve this, the crossover of multiple beams must be removed from the optical axis. This can be achieved by using an image forming tool or a beam tilting deflector.

FIG. 9A shows how the plurality of beams 102_1, 102_2, 102_3 are tilted by the image forming tool 122 in the multi-charged particle beam device 100A. The skew angle α1 of FIG. 1B is zero, and the skew angles α1, α2, α3 of FIG. 9A are increased by the same amount, so that the intersection of the beams 102_1, 102_2, 102_3 is removed from the optical axis 100_1 and moved to or Approaching the first focusing surface of the objective lens 131. The beams 102_1, 102_2, 102_3 therefore land obliquely on the surface 7 of the sample 8 at the same skew or landing angle. Likewise, the previously described multi-charged particle beam devices 300A, 400A, 500A, and 600A can tilt the beams by corresponding image forming tools. For the beams 102_1, 102_2, 102_3 of the multi-charged particle beam devices 300A, 400A, and 600A, the path is similar to the path of the beams of Figure 9A. The paths of the beams of the multi-charged particle beam device 500A may be slightly different, as shown in Fig. 9B. The skew angle α of FIG. 5B is zero, and the skew angles α1, α2, and α3 of the three beams 102_1, 102_2, and 102_3 of FIG. 9B are offset by three second real images 102_1m, 102_2m on the intermediate image plane PP1. 102_3m Same or substantially the same distance. Thus, the intersection of the beams 102_1, 102_2, 102_3 bent by the field lens 534 is still on or near the first focusing surface, but offset from the optical axis 500_1.

Figure 10 shows a multi-charged particle beam device 700 that tilts beams 102_1, 102_2, 102_3 with a beam tilt deflector 135 in accordance with another embodiment of the present invention. Compared to FIG. 1B, the beam tilt deflector 135 simultaneously deflects the beams 102_1, 102_2, 102_3 such that their intersecting CVs are moved out of the optical axis and moved to the first focus plane of the objective lens 131 or close to the first focus. On the surface. Likewise, the beam tilt deflector 135 can also be applied to other embodiments of the present invention, such as multi-charged particle beam devices 300A, 400A, 500A, 600A, to deflect multiple beams together. The beam tilt deflector 135 may be disposed between the electron source conversion unit and the front focusing surface of the objective lens, and preferably, adjacent to the electron source conversion unit. Further, if the skew scanning unit of the foregoing embodiments is on the front focusing surface of the objective lens, the skew scanning unit can move the intersection of the plurality of beams, so that the beam tilt deflector 135 is not required.

Although the multi-charged particle beam device of each embodiment of the present invention uses one or two methods to change the size, orientation, or angle of incidence of the field of view, those skilled in the art can make various combinations according to this, as long as they are not mutually exclusive. All belong to the concept and scope of the invention. For example, in the multi-charged particle beam device of an embodiment, a movable image forming tool can be used, and an animal mirror can also be used. In another embodiment, an animal mirror, a conversion lens, and a field lens are used. Although the various embodiments are exemplified by the multiple electron beam apparatus 200A of FIG. 2B, the apparatus, components, and/or methods of the present invention may be applied to other conventional multiple electron beam apparatus, such as the multiple electron beam apparatus of FIG. 1A. These variations are within the scope of the invention.

In summary, based on various conventional multi-charged particle beam devices proposed in the related applications, the present invention provides a novel multi-charged particle beam device comprising a plurality of methods or elements for making the total field of view of the device variable in size, orientation, and / or angle of incidence. Therefore, the novel multi-charged particle beam device provides more flexibility, which increases the observation speed of the sample and the observation quality of the sample. More specifically, the novel multi-charged particle device, when used as a yield management tool, has the opportunity to achieve high productivity and detect a wider variety of defects. The present invention proposes three methods to vary the spacing of multiple beams incident on the surface of the sample. The methods include using a movable image forming tool in the electron source conversion unit, or using an animal mirror, or using a conversion lens and a lens between the electron source conversion unit and the objective lens to change the total field of view. The present invention proposes three methods to rotate the array of detection points such that the orientation of the total field of view is changed. The methods include using an electromagnetic composite objective and changing its electric field, using an objective lens having two magnetic lenses and setting such that the two magnetic lenses have opposite polarities, using a magnetic lens and a conversion lens or field lens, or a magnetic lens plus Conversion lens and field lens. The present invention proposes three methods whereby the intersection of a plurality of beams is removed from the optical axis such that the landing angles of the plurality of beams on the surface of the sample are changed the same. The offset of the beams can be accomplished by an image forming tool, or by adding a beam tilt deflector, or by tilting the scanning unit.

The above embodiments are merely illustrative of the technical spirit and characteristics of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention. Various equivalent changes or modifications may be made without departing from the spirit and scope of the invention, and are intended to be included within the scope of the invention.

7‧‧‧ surface

8‧‧‧ samples

101‧‧‧Electronic source

102‧‧‧One electron beam

110‧‧‧ Concentrating lens

120‧‧‧Electronic source conversion unit

121‧‧‧Ball Limiting Tool

122‧‧‧Image Forming Tools

123‧‧‧Pre-beam bending tool

124‧‧‧Image Forming Tools

131‧‧‧ Objective lens

131-1‧‧‧ Objective lens

210‧‧‧ movable concentrating lens

210_2‧‧‧Change range

220‧‧‧Electronic source conversion unit

300‧‧‧Multiple charged particle beam device

320‧‧‧Electronic source conversion unit

322‧‧‧Removable image forming tools

420‧‧‧Electronic source conversion unit

533‧‧‧Converting lens

534‧‧ Field lens

631‧‧‧ objective lens

100_1‧‧‧ optical axis

100_1‧‧‧ optical axis

100_1‧‧‧ optical axis

100A‧‧‧Multiple charged particle beam device

102_1‧‧·beam

102_1‧‧‧Detection point

102_1m‧‧‧Second Real Image

102_2‧‧·beam

102_2‧‧‧Detection point

102_2m‧‧‧Second Real Image

102_3‧‧·beam

102_3‧‧‧Detection points

102_3m‧‧‧Second Real Image

121_1‧‧‧Electron beam limiting opening

121_2‧‧‧Electron beam limiting opening

121_3‧‧‧Electron beam limiting opening

122_1‧‧‧Electronic optics

122_2‧‧‧Electronic optics

122_3‧‧‧Electronic optics

123_1‧‧‧Pre-bending micro-deflector

123_2‧‧‧Pre-curved micro-bias

123_3‧‧‧Pre-curved micro-bias

124_1‧‧‧Electronic optics

124_2‧‧‧electron optical components

124_3‧‧‧electron optical components

131_c1‧‧‧ coil

131_e1‧‧‧Field-controlled electrode

131_mp1‧‧‧ magnetic pole

131_mp2‧‧‧Magnetic pole

131_y1‧‧‧ yoke

135‧‧‧beam tilt deflector

300_1‧‧‧ optical axis

300A‧‧‧Multiple charged particle beam device

322_0‧‧‧effective skew plane

322_1‧‧‧electron optics

322_2‧‧‧electron optical components

322_3‧‧‧electron optical components

322_or‧‧‧Change range

400A‧‧‧Multiple charged particle beam device

500_1‧‧‧ optical axis

500A‧‧‧Multiple charged particle beam device

510A‧‧‧Multiple charged particle beam device

520A ‧‧‧Multiple charged particle beam device

533_11‧‧‧Electrostatic conversion lens

533_12‧‧‧Magnetic Conversion Lens

533-1‧‧‧Electromagnetic composite conversion lens

534_11‧‧‧Electrostatic field lens

534_12‧‧‧Magnetic lens

534-1‧‧‧Electromagnetic composite field lens

600_1‧‧‧ optical axis

600A‧‧‧Multiple charged particle beam device

631_1‧‧‧First principle plane

631_2r‧‧‧Change range

631-1‧‧‧ objective lens

631-1_e2‧‧‧electrode

631-2‧‧‧ Objective lens

631-2_e2‧‧‧electrode

631-2_e3‧‧‧electrode

631-3‧‧‧ Objective lens

631-3_2‧‧‧ yoke

631-3_c2‧‧‧ coil

700_1‧‧‧ optical axis

700A‧‧‧Multiple charged particle beam device

G1‧‧‧Magnetic flow spacing

G2‧‧‧Magnetic flow spacing

PP1‧‧‧ intermediate image plane

Ps‧‧‧ spacing

11‧‧‧ skew angle

22‧‧‧ skew angle

33‧‧‧ skew angle

Γ2‧‧‧bend angle

Γ3‧‧‧bend angle

The technical content of this case will be easily understood through the following description and drawings. Similar component numbers in the drawings represent identical or similar structural elements, and the drawings include:

1A and 1B are schematic views showing the structure of a conventional multi-electron beam apparatus as in the fifth application listed in the related matter of the present invention.

Figure 1C is a schematic view showing the structure of a conventional electromagnetic composite objective lens.

2A and 2B are schematic views showing the total field of view of variable size and orientation.

Fig. 3A is a schematic view showing the structure of a multi-charged particle beam device according to an embodiment of the present invention.

Figures 3B and 3C are schematic views showing the total field of view of the variable size and orientation of the multi-charged particle beam apparatus of the embodiment of Figure 3A.

4A is a schematic view showing the structure of a multi-charged particle beam device according to another embodiment of the present invention.

4B and 4C are schematic views showing the total field of view of the variable size and orientation of the multi-charged particle beam apparatus of the embodiment of Fig. 4A.

Fig. 5A is a schematic view showing the structure of a multi-charged particle beam device according to another embodiment of the present invention.

Figures 5B and 5C are schematic views showing the total field of view of the variable size and orientation of the multi-charged particle beam device of the embodiment of Figure 5A.

Fig. 6A is a schematic view showing the structure of a multi-charged particle beam device according to another embodiment of the present invention.

Figures 6B and 6C are schematic views showing the total field of view of the variable size and orientation of the multi-charged particle beam apparatus of the embodiment of Figure 5A.

7A through 7C show the structure of the animal mirror of Fig. 6A according to another embodiment of the present invention.

8A and 8B are schematic views showing the structure of a multi-charged particle beam device according to another embodiment of the present invention.

Figure 9A shows tilting a multiple electron beam of the multiple electron beam apparatus of Figure 1B in accordance with another embodiment of the present invention.

Figure 9B shows the tilt of a multi-charged particle beam of a multi-charged particle beam device in accordance with the embodiment of Figure 5A of the present invention.

Figure 10 is a schematic view showing the structure of a multi-charged particle beam device according to another embodiment of the present invention.

Claims (13)

A multi-charged particle beam device for observing a surface of a sample, comprising: an electron source; a collecting lens located below the electron source; an electron source converting unit located below the collecting lens; an objective lens located at Under the electron source conversion unit; a skew scanning unit located below the electron source conversion unit; a sample stage located below the objective lens; a beam splitter located below the electron source conversion unit; and a secondary projection imaging system And an electronic detecting device having a plurality of detecting elements; wherein the electron source, the collecting lens, and the objective lens are arranged with an optical axis of the multi-charged particle beam device, the sample stage supporting the sample, the sample The surface facing the objective lens; wherein the electron source conversion unit comprises a beam limiting tool having a plurality of beam limiting openings, and an image forming tool having a plurality of electron optical elements, the image forming tool being along the optical axis Moving; wherein the electron source generates a primary electron beam along the optical axis, and the collecting lens focuses the primary electron beam; wherein the electron beam A plurality of beams of the electron beam respectively pass through the beam confinement openings, and are deflected by the electron optical elements toward the optical axis to respectively form a plurality of virtual images of the electron source; wherein the objective lens is more Focusing on the surface of the sample to form a plurality of detection points on the surface, the skew scanning unit deflecting the plurality of beams to perform a plurality of scans in an observation area of the surface Scanning the plurality of detection points in the region; wherein the plurality of detection points respectively generate a plurality of secondary electron beams from the plurality of scanning regions, and the secondary electron beams are guided by the beam splitter to the secondary projection imaging system The secondary projection imaging system focuses and maintains the plurality of secondary electron beams, which are respectively detected by the plurality of detecting elements, each of the detecting elements thus providing an image signal corresponding to the scanning area. A multi-charged particle beam device for observing a surface of a sample, comprising: an electron source; a collecting lens located below the electron source; an electron source converting unit located below the collecting lens; an objective lens located at Under the electron source conversion unit; a skew scanning unit located below the electron source conversion unit; a sample stage located below the objective lens; a beam splitter located below the electron source conversion unit; and a secondary projection imaging system And an electronic detecting device having a plurality of detecting elements; wherein the electron source, the collecting lens, and the objective lens are arranged with an optical axis of the multi-charged particle beam device, the sample stage supporting the sample, the sample The surface of the electron source conversion unit includes a beam limiting tool having a plurality of beam limiting openings, a first image forming tool having a plurality of first electron optical elements, and a plurality of a second image forming tool of the second electro-optical element, the second image forming tool being located below the first image forming tool and a radial movement, and the first image forming tool or the second image forming tool is used as an active image forming tool; wherein the electron source generates a primary electron beam along the optical axis, and the collecting lens focuses the primary electron a beam; wherein the plurality of beams of the primary electron beam respectively pass through the beam confinement openings, and are deflected by the electron optical elements toward the optical axis to respectively form a plurality of virtual images of the electron source; The objective lens focuses the plurality of beams on the surface of the sample to form a plurality of detection points on the surface, the deflection scanning unit deflecting the plurality of beams to be within an observation area of the surface Scanning the plurality of detection points in a plurality of scanning regions; wherein the plurality of detection points respectively generate a plurality of secondary electron beams from the plurality of scanning regions, the secondary electron beams being guided by the beam splitter a secondary projection imaging system that focuses and holds the plurality of secondary electron beams, each of which is detected by the plurality of detecting elements, each of the detecting elements An image signal for a corresponding one of the scanning area. A multi-charged particle beam device for observing a surface of a sample, comprising: an electron source; a collecting lens located below the electron source; an electron source converting unit located below the collecting lens; an objective lens located at Under the electron source conversion unit; a skew scanning unit located below the electron source conversion unit; a sample stage located below the objective lens; a beam splitter located below the electron source conversion unit; and a secondary projection imaging system And an electronic detecting device having a plurality of detecting elements; wherein the electron source, the collecting lens, and the objective lens are arranged with an optical axis of the multi-charged particle beam device, and a first principle plane of the objective lens is Moving along the optical axis, the sample stage supports the sample, the surface of the sample facing the objective lens; wherein the electron source conversion unit comprises a beam limiting tool having a plurality of beam limiting openings, and having a plurality of electron optics An image forming tool of the component; wherein the electron source generates a primary electron beam along the optical axis, and the collecting lens focuses the primary electron beam; The plurality of beams of the primary electron beam respectively pass through the plurality of beam confinement openings, and are deflected by the electron optical elements toward the optical axis to respectively form a plurality of virtual images of the electron source; wherein the objective lens Focusing the plurality of beams on the surface of the sample to form a plurality of detection points on the surface, the skew scanning unit deflecting the plurality of beams to be within a viewing area of the surface Scanning the plurality of detection points in the plurality of scanning regions; wherein the plurality of detection points respectively generate a plurality of secondary electron beams from the plurality of scanning regions, and the secondary electron beams are guided by the beam splitter to the second a projection imaging system that focuses and holds the plurality of secondary electron beams, each of which is detected by the plurality of detecting elements, each of the detecting elements thus providing a corresponding one of the scanning areas Image signal. A multi-charged particle beam device for observing a surface of a sample, comprising: an electron source; a collecting lens located below the electron source; an electron source converting unit located below the collecting lens; a conversion lens, Located below the electron source conversion unit; a lens below the conversion lens; an objective lens under the field lens; a skew scanning unit located below the electron source conversion unit; a sample stage located below the objective lens; a beam splitter located below the electron source conversion unit; a secondary projection imaging system; and an electronic detection device having a plurality of detecting elements; wherein the electron source, the collecting lens, the converting lens, the field a lens, and the objective lens is aligned with an optical axis of the multi-charged particle beam device, the sample stage supporting the sample, the surface of the sample facing the objective lens; wherein the electron source conversion unit comprises a plurality of beam limiting openings a beam limiting tool, and an image forming tool having a plurality of electron optical components; wherein the electron source generates a primary electricity A beam along the optical axis, the concentrating lens focusing the primary electron beam; wherein the plurality of beams of the primary electron beam respectively pass through the beam confinement openings and are deflected by the electron optical elements toward the light a plurality of first virtual images respectively forming the electron source; wherein the conversion lens images the plurality of first virtual images on an intermediate image plane, thereby forming a plurality of second real images on the intermediate image plane The field lens is located on the intermediate image plane and bends the plurality of beams, and the lens images the plurality of second real images on the surface of the sample to form a plurality of detection points on the surface, the skew scan The unit deflects the plurality of beams to scan the plurality of detection points in a plurality of scan areas in an observation area of the surface; wherein the plurality of detection points respectively generate a plurality of two from the plurality of scan areas Secondary electron beams directed by the beam splitter to the secondary projection imaging system, the secondary projection imaging system focusing and maintaining the plurality of secondary electron beams And being detected by the plurality of detecting components, each of the detecting components thus providing an image signal corresponding to the scanning area. A method for arranging a multi-charged particle beam device for observing a surface of a sample, comprising the steps of: arranging an image forming tool of an electron source conversion unit that is movable along an optical axis; forming the image The tool respectively forms a plurality of virtual images of an electron source; imaging a plurality of virtual images on the surface by an objective lens and forming a plurality of detection points on the surface; and moving the image forming tool to change between the plurality of detection points Pitch. A method for configuring a multi-charged particle beam device for observing a surface of a sample, comprising the steps of: configuring an electron source conversion unit having a first image forming tool and a second image forming tool, wherein the The distance between the second image forming tool and the electron source is longer than the distance between the first image forming tool and the electron source, and the second image forming tool is movable along the radial direction of the multi-charged particle beam device; The image forming tool or the second image forming tool is used as an active image forming tool, wherein when the first image forming tool is used, the second image forming tool is removed; and the active image forming tool respectively forms the plural of the electron source a virtual image; imaging a plurality of virtual images on the surface by an objective lens and forming a plurality of detection points on the surface; and changing the active image forming tool to the first image forming tool or the second image forming tool to Changing the spacing between the plurality of probe points. A method of arranging a multi-charged particle beam device for observing a surface of a sample comprises the steps of: arranging an objective lens having a first principle plane, the objective lens being along an optical axis of the multi-charged particle beam device Moving, forming, by an image forming tool of an electron source converting unit, a plurality of virtual images of an electron source; imaging the plurality of virtual images on the surface with the objective lens and forming a plurality of detecting points on the surface; and moving the The first principle plane is to change the spacing between the plurality of probe points. A method for arranging a multi-charged particle beam device for observing a surface of a sample, comprising the steps of: arranging an objective lens having a lower magnetic lens and an electrostatic lens in the multi-charged particle beam device; An image forming tool of the converting unit respectively forms a plurality of virtual images of an electron source; imaging the plurality of virtual images on the surface with the objective lens and forming a plurality of detecting points on the surface; and changing the lower magnetic lens and the static electricity A ratio of the zoom magnification of the lens to select an orientation of the plurality of probe points. A method for arranging a multi-charged particle beam device for observing a surface of a sample comprises the steps of: deflecting a plurality of beams of an electron source by an image processing tool of an electron source conversion unit to form a plurality of first virtual images of the electron source; imaging the plurality of first virtual images on the surface by an objective lens and forming a plurality of probe points on the surface; and setting the plurality of the plurality of probes due to the image processing tool The skew angle of the beam is such that the plurality of beams land on the surface at the same or substantially the same landing angle. A method for arranging a multi-charged particle beam device for observing a surface of a sample comprises the steps of: deflecting a plurality of beams of an electron source by an image processing tool of an electron source conversion unit to form a plurality of first virtual images of the electron source; imaging the plurality of first virtual images on an intermediate image plane by a conversion lens and forming a plurality of second real images; and using a field lens disposed on the intermediate image plane a plurality of beams; and imaging a plurality of second real images onto the surface with an objective lens and forming a plurality of probe points on the surface. A device comprising: a particle source for providing a primary charged particle beam; a particle source conversion unit dividing the primary charged particle beam into a plurality of charged particle beams and forming a plurality of images of the particle source; An objective lens is located in the particle source conversion unit for projecting the plurality of images onto a surface of the sample; wherein a spacing of the plurality of charged particle beams on the surface is changed by changing the plurality of charged particle beams The objective lens is adjusted before the skew angle. A device comprising: a particle source for providing a primary charged particle beam; a tool for dividing the primary charged particle beam into a plurality of charged particle beams and forming a plurality of images of the particle source; For projecting a plurality of images onto a surface of a sample, forming a plurality of probe points on the surface; and a tool for adjusting a spacing between the plurality of probe points on the surface. A method for observing a surface of a sample, comprising the steps of: providing a plurality of charged particle beams having a plurality of intersections; projecting the plurality of intersections on the surface of the sample to form a plurality of detection points on the surface of the sample; scanning the The plurality of probe points on the surface of the sample; and changing the skew angle of the plurality of charged particle beams such that the spacing between the plurality of probe points is adjusted.