JP6177093B2 - Charged particle beam equipment - Google Patents

Description

  The present invention relates to a charged particle beam apparatus such as a scanning electron microscope, and relates to a technique for reducing sample drift caused by a temperature change in an installation environment of the apparatus.

  A charged particle beam device irradiates a sample with a charged particle beam such as an electron beam in a sample chamber kept in a vacuum, and detects secondary electrons generated from the sample at this time, thereby displaying an enlarged observation image of the sample surface. get. In addition, by detecting secondary particles such as backscattered electrons, characteristic X-rays, cathode light (cathode luminescence), etc. generated simultaneously with secondary electrons from the sample, sample analysis such as elemental composition analysis of the sample, composition analysis of crystal orientation, etc. Can also be done.

  In a charged particle beam apparatus, a sample is mounted on and supported by a sample stage when irradiated with a charged particle beam. The sample stage on which the sample is mounted is moved horizontally, moved up and down, rotated, or tilted in the sample chamber according to the observation conditions (observation region) and observation direction on the sample, and charged particles on the sample. The irradiation position and irradiation direction of the line are adjusted.

  By the way, in sample analysis using a charged particle beam apparatus, depending on the analysis conditions such as the analysis range (analysis region) and analysis procedure on the sample, the analysis processing time may take a long time. The time for mounting and holding on the stage also becomes longer. Therefore, in a charged particle beam device that can also perform sample analysis, the acquired image moves with respect to the target position that is the original observation / analysis position on the sample according to the observation / analysis conditions as the working time elapses. Sample drift may occur. If sample drift occurs during sample analysis, the analysis target position differs from the target position, and sample analysis at an incorrect position is performed.

  One cause of this sample drift is that the temperature of the environment in which the charged particle beam device is installed changes during this long-time observation and analysis work, causing the device to thermally deform. As a result, the charged particle beam sample The position irradiated on the surface may be shifted.

  Conventionally, as a technique for reducing such sample drift, for example, there is a drift reduction technique as disclosed in WO 2011/145290 (Patent Document 1). Patent Document 1 discloses a drift reduction technique that includes a thermometer that measures a change in the temperature of a charged particle beam device and a heating device that absorbs the temperature change of the sample stage in accordance with the temperature change. Yes.

WO2011 / 145290 Publication

  The sample drift is partly due to the temperature change in the installation environment of the apparatus during the observation / analysis work of the sample using the charged particle beam apparatus, and the apparatus is thermally deformed. The influence of the temperature change appears quickly in the device part in contact with the environmental atmosphere (air).

  Therefore, in the technique described in Patent Document 1, the thermometer is arranged on the outer surface of the sample chamber casing of the charged particle beam apparatus, and the temperature of the apparatus casing that is in contact with the temperature change of the installation environment or the environmental atmosphere. It is configured to measure changes. Then, by changing the output of the heating device so as to absorb the temperature change according to a predetermined relational expression set in advance with respect to the temperature change of the device housing measured by the thermometer, the charged particle beam device It is configured to reduce sample drift.

  However, in the technique described in Patent Document 1, since the heating device is configured to be provided on the sample stage disposed in the sample chamber kept in a vacuum, the heating device is disposed on the outer surface of the device housing. It takes time until the influence of the environmental temperature change measured by the thermometer actually propagates to the inside of the sample chamber equipped with the heating device and the sample stage, and in terms of responsiveness to thermal deformation of the device. There was a problem.

  That is, the technique described in Patent Document 1 indirectly measures a sample drift caused by thermal deformation of the apparatus by measuring a temperature change in the installation environment of the apparatus with a thermometer. However, the appearance of thermal deformation in the device due to temperature changes in the installation environment of the device is low reproducibility, and it is difficult to accurately measure the sample drift even if the temperature of the installation environment or the temperature of the device itself is measured. There was a problem of being.

  The present invention has been made in view of the above problems, and is generated in a charged particle beam device due to a temperature change in the installation environment by directly measuring the amount of thermal deformation generated in the charged particle beam device due to a temperature change in the installation environment. An object of the present invention is to provide a charged particle beam apparatus that measures sample drift with high accuracy and reduces drift due to temperature changes in the installation environment.

  In order to solve the above problems, a charged particle beam apparatus according to the present invention includes a sample chamber for irradiating a sample with a charged particle beam, a sample stage on which a sample for irradiating a charged particle beam is mounted, and a sample chamber. A charged particle beam apparatus comprising a stage case having an inner surface facing and an outer surface facing an external environmental atmosphere, and supporting a sample stage and placing a sample mounted on the sample stage in the sample chamber The deformation amount measuring means for measuring the deformation amount of the stage case, the temperature adjusting means for heating and / or cooling the outer surface of the stage case, and the deformation amount measured by the deformation amount measuring means are mounted on the sample stage. And a control means for controlling the operation of the temperature adjusting means so that the irradiation position of the charged particle beam on the sample does not move due to the temperature change of the environmental atmosphere.

  ADVANTAGE OF THE INVENTION According to this invention, the charged particle beam apparatus which can reduce the sample drift resulting from the temperature change of an installation environment highly accurately and with sufficient responsiveness can be provided.

  Moreover, even if the appearance of thermal deformation in the device due to temperature changes in the installation environment is low in reproducibility, the current thermal deformation state of the device can be directly grasped from the amount of deformation (the amount of strain to be measured). It is possible to correct the sample drift.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is an overall configuration diagram of an SEM according to an embodiment of a charged particle beam apparatus of the present invention. It is a schematic diagram which shows the structure of the sample stage in SEM shown in FIG. It is a block diagram of one Example of the drift correction means with which SEM shown in FIG. 1 was equipped. It is a verification graph of the relationship between the drift amount of sample drift and the distortion amount which arose in the stage case. It is a block diagram of another Example of the drift correction | amendment means with which SEM concerning this Embodiment was equipped. It is the figure which showed typically the form of the stage case at the time of environmental temperature fall-decreasing during the observation / analysis operation | work over a long time, and a stage case having contracted and thermally deformed. It is the figure which showed typically the form of the stage case when environmental temperature raises and changes during expansion | swelling observation and analysis work for a long time, and a stage case expands and deforms. It is state explanatory drawing of the sample stage in SEM which the arrangement | positioning attitude | position in a sample chamber changed with the shrinkage | contraction thermal deformation of the stage case.

  Hereinafter, an embodiment of a charged particle beam device according to the present invention will be described with reference to the drawings. In the description, a scanning electron microscope (SEM) as a kind of charged particle beam apparatus will be described as an example. However, the charged particle beam apparatus according to the present invention is not limited to the SEM.

  FIG. 1 is an overall configuration diagram of an SEM according to an embodiment of a charged particle beam apparatus according to the present invention.

  In FIG. 1, an SEM 100 includes a lens barrel 102 that accommodates an electron optical system device that constitutes an electron optical system 121, and a sample chamber housing 103 in which a sample chamber 111 that accommodates a sample 110 to be observed is formed. Have. The lens barrel 102 has a structure in which it is mounted and fixed integrally on the upper surface of the sample chamber casing 103. The lens barrel 102 and the sample chamber casing 103 constitute an apparatus casing 101 of the SEM 100. When the sample 110 to be analyzed housed in the sample chamber 111 is exchanged, the peripheral surface of the sample chamber housing 103 is opened to the outside of the apparatus housing 101, and always including observation and analysis, A sample exchange port 112 that is airtightly closed by the sample exchange port lid 160 is formed.

  In the apparatus housing 101, the inside of the lens barrel 102 and the sample chamber 111 in which the sample exchange port 112 is sealed can be isolated from the environmental atmosphere (atmosphere) in which the SEM 100 is installed, and the airtight structure is maintained. It has become. Further, between the lens barrel 102 and the sample chamber housing 103, a structure in which the primary electron beam 120 generated by the electron optical system 121 of the lens barrel 102 can be irradiated to the sample 110 to be analyzed in the sample chamber 111. Yes.

  The inside of the lens barrel 102 is evacuated by an evacuation means such as a vacuum pump (not shown), and is always kept in a high vacuum state. In addition, the sample chamber 111 of the sample chamber housing 103 has an exhaust means such as a vacuum pump (not shown) while the sample exchange port 112 is sealed and the observation / analysis operation is performed on the sample 110 to be observed / analyzed. Is evacuated to maintain a vacuum state suitable for observation and analysis. The internal pressure of the sample chamber 111 is such that when the sample exchange port 112 is opened and the sample is exchanged, the vacuum state is restored to the atmospheric pressure state in advance when the sample exchange port 112 is opened. After the sample exchange, when the sample exchange port 112 is closed, the vacuum state suitable for observation / analysis is restored.

  The lens barrel 102 houses components of the electron optical system 121 such as an electron gun 122, a converging lens 123, an objective lens 124, a scanning deflector 125, and the like. Each of the component devices 122, 123, 124, and 125 is signal-connected to an electron optical system control unit 201 provided outside the apparatus housing 101. In the illustrated example, the lens barrel 102 is provided with a secondary electron detector 131 that detects the secondary electrons 130 emitted from the sample 110 by irradiation of the primary electron beam 120. The secondary electron detector 131 is signal-connected to an image generation unit 202 provided outside the apparatus housing 101.

  On the other hand, the sample 110 to be analyzed is mounted on the sample stage 150 and accommodated in the sample chamber 111 of the sample chamber casing 103. Further, in the illustrated example, the sample chamber casing 103 is emitted simultaneously with the secondary electrons 130 from the sample 110 by irradiation of the primary electron beam 120, for example, reflected electrons, characteristic X-rays, cathode light (cathode luminescence). A secondary particle detector for detecting secondary particles used to perform sample analysis such as elemental composition analysis of the sample 110 and composition analysis such as crystal orientation is provided. Here, as a secondary particle detector for sample analysis, energy dispersive X-ray analysis (EDX () which detects characteristic X-rays 140 emitted from the sample 110 together with the secondary electrons 130 by irradiation of the primary electron beam 120 is detected. Energy dispersive X-ray spectrometry)) detector 141 is provided. The EDX detector 141 is signal-connected to an EDX processing unit 205 provided outside the apparatus housing 101.

  In the illustrated example, the secondary electron detector 131 and the secondary particle detector for sample analysis (EDX detector 141) are arranged at the lens barrel 102 and the sample chamber housing 103, respectively. As long as it is a place where the electron 130 and secondary particles for sample analysis (characteristic X-rays 140 in the illustrated example) can be detected, either the lens barrel 102 or the sample chamber housing 103 may be used.

  When observing and analyzing the sample 110 using the SEM 100, the electron optical system control unit 201 controls each of the constituent devices 122, 123, 124, and 125 of the electron optical system 121 according to preset observation and analysis conditions. Irradiation control of the primary electron beam 120 is performed on the sample 110 to be observed / analyzed accommodated in the chamber 111. For example, when acquiring an enlarged observation image (SEM image) of the sample surface related to the observation / analysis region of the sample 110 to be observed / analyzed, the electron optical system control unit 201 sets the observation / analysis conditions of the sample 110 in advance. Based on the set recipe, the primary electron beam 120 generated and emitted by the electron gun 122 for each observation / analysis region on the sample surface where the sample 110 is observed / analyzed is converted into a converging lens 123 and an objective lens 124. The scanning deflector 125 scans the irradiation position of the primary electron beam 120 on the sample surface corresponding to the observation / analysis region corresponding to the target position.

  In addition to the detection output of the secondary electron detector 131, the image generation unit 202 is also supplied with a scanning control signal of the primary electron beam 120 supplied from the electron optical system control unit 201 to the scanning deflector 125. The image generation unit 202 uses the intensity of the secondary electrons 130 detected by the secondary electron detector 131 as a luminance modulation input of an image that is scanned and generated in synchronization with the scanning of the primary electron beam 120, so that the analysis target An enlarged observation image of the sample surface related to the observation / analysis region of the sample 110 is generated. The enlarged observation image data generated by the image generation unit 202 is output to the observation image display unit 203, and an enlarged observation image is displayed.

  In addition to the detection output of the EDX detector 141, the EDX processing unit 205 is also supplied with a scanning control signal of the primary electron beam 120 supplied from the electron optical system control unit 201 to the scanning deflector 125. The EDX processing unit 205 acquires a signal intensity proportional to the energy of the characteristic X-ray 140 detected by the EDX detector 141 in synchronization with the scanning of the primary electron beam 120, and based on this, the sample 110 to be analyzed is acquired. The EDX spectrum and element distribution image (Mapping image) related to the observation / analysis region are generated, and the constituent elements of the sample in the observation / analysis region are obtained. The EDX spectrum data and element distribution image data generated by the EDX processing unit 205 are output to the analysis image display unit 206 and displayed.

  In performing such observation / analysis, the sample 110 to be analyzed is mounted on the sample stage 150 and accommodated in the sample chamber 111, and the observation / analysis range (observation / analysis region) on the sample surface is observed / analyzed. Depending on the analysis conditions, the sample chamber 111 is horizontally moved, moved up and down, rotated, or tilted to adjust the irradiation position and irradiation direction of the charged particle beam (primary electron beam 120) on the sample surface.

  FIG. 2 is a schematic diagram showing the configuration of the sample stage in the SEM shown in FIG.

  The sample stage 150 is configured to move the mounted sample 110 horizontally, vertically, rotate, or tilt in the sample chamber 111 according to observation / analysis conditions such as an observation position and an observation direction on the sample. The irradiation position of the primary electron beam 120 above is displaced, the orientation of the sample surface with respect to the optical axis direction of the electron optical system 121 is adjusted, and the like.

  In the illustrated example, the sample stage 150 includes a sample holder 151, a rotation table 152, a Y table 153, an X table 154, a T base (tilt base) 155, a tilt shaft 156, and a Z table 157.

  The sample holder 151 has a sample mounting surface on which the sample 110 is bonded and mounted, is positioned with respect to the rotation table 152, and is detachably screwed. As a result, the sample 110 can be replaced with the sample holder 151 with respect to the rotation table 152.

  The rotation table 152 is rotatably supported with respect to the Y table 153 with a rotation axis perpendicular to the sample mounting surface of the sample holder 151 positioned and fixed to the rotation table 152 as a rotation center. The sample 110 mounted and fixed on the sample holder 151 rotates integrally with the rotation table 152 in response to the rotation of the rotation table 152 on the Y table 153 by driving a rotation table motor (not shown). Displace.

  The Y table 153 is supported so as to be movable with respect to the X table 154 via a Y-axis direction guide (not shown) along the Y-axis direction parallel to the sample mounting surface of the sample holder 151 positioned and fixed to the rotation table 152. Has been. The sample 110 mounted and fixed on the sample holder 151 corresponds to the rotation table 152 corresponding to the movement of the Y table 153 along the Y axis direction on the X table 154 by driving a Y table motor (not shown). The Y table 153 moves and displaces integrally with the Y-axis direction.

  The X table 154 is a guide (not shown) in the X axis direction along the X axis direction that is parallel to the sample mounting surface of the sample holder 151 fixed to the rotation table 152 and perpendicular to the Y axis with respect to the T base 155. It is supported so that it can move through. The sample 110 mounted and fixed on the sample holder 151 corresponds to the rotation table 152, corresponding to the movement of the X table 154 along the X-axis direction on the T base 155 by driving an unillustrated X table motor. The Y table 153 is moved and displaced in the X-axis direction integrally with the X table 154.

  The T base 155 has a base table surface on which the X table 154 is movably attached along the X axis direction via an X axis direction guide on the peripheral surface on one end side, and a tilt on the end surface on the other end side. The shaft 156 is integrally screwed. The tilt shaft 156 protrudes from the end surface on the other end side of the T base 155 and extends along the X-axis direction.

The T base 155 is attached to the Z table 157 so that the tilt shaft 156 is rotatably supported. The T base 155 is rotated and displaced with respect to the Z table 157 about the axis of the tilt shaft 156 by driving a tilt motor (not shown), so that the base table surface rotates around the axis of the tilt shaft 156. Dynamic displacement. The sample 110 mounted and fixed on the sample holder 151 corresponds to the rotation table 152, the Y table 153, and the X table corresponding to the rotation of the T base 155 about the axis of the tilt shaft 156 by driving the tilt motor. Each 154 is rotated and displaced integrally with the T base 155 around the axis of the tilt shaft 156, and the sample mounting surface of the sample holder 151 is in a horizontal state perpendicular to the optical axis Z ₀ of the electron optical system 121. It is designed to tilt.

  The Z table 157 extends along a predetermined direction orthogonal to the X-axis direction, which is the extending direction of the tilt shaft 156, with respect to a stage case 161 (described later) that is detachably attached to the sample exchange port 112 of the sample chamber housing 103. , And are supported movably through a Z-axis direction guide 165. The sample 110 mounted and fixed on the sample holder 151 corresponds to the rotation table 152, Y corresponding to the movement of the Z table 157 along the predetermined direction in the stage case 161 by driving a Z table motor (not shown). The table 153, the X table 154, and the T base 155 are moved and displaced along a predetermined direction integrally with the Z table 157.

  In the sample stage 150, a rotation table motor (not shown) for rotating and rotating a rotation table 152 about a rotation axis perpendicular to the sample mounting surface of the sample holder 151 as a rotation center, and a Y table 153 in the Y-axis direction. Y table motor for moving and displacing along the X table, X table motor for moving and displacing the X table 154 along the X axis direction, and T base 155 for rotating and displacing the tilt shaft 156 as the rotation center Z table motors for moving and displacing the Z table 153 along a predetermined direction orthogonal to the X-axis direction are respectively connected to the electron optical system control unit 201, and the sample 110 is observed using the SEM 100.・ In analysis, according to observation / analysis conditions set in advance, especially observation / analysis area, observation / analysis direction, etc. They are respectively driven and controlled. In this case, the electron optical system control unit 201 controls irradiation of the primary electron beam 120 by controlling each of the constituent devices 122, 123, 124, and 125 of the electron optical system 121 according to observation / analysis conditions, and performs rotation. The table 152, the Y table 153, the X table 154, the T base 155, and the Z table 157 are controlled to move or rotate, and the irradiation position of the primary electron beam 120 on the sample surface of the sample 110 mounted on the sample holder 151 is determined. It is displaced in the sample chamber 111 or the direction of the sample surface with respect to the optical axis direction of the electron optical system 121 is adjusted.

  In the example shown in the figure, the stage case 161 is formed of a hollow frame having a quadrangular end face that is large enough to surround the sample exchange port 112 formed on the peripheral surface of the sample chamber casing 103. The opening end surface on one end side of the stage case 161 is a contact side end surface 163 that is in contact with and closely contacted with the outer peripheral surface of the sample chamber casing 103 while surrounding the opening edge of the sample exchange port 112 of the sample chamber casing 103. ing. On the other hand, the opening end surface 164 on the other end side of the stage case 161 is an opening provided when the sample stage 150 is assembled, during maintenance of the sample stage 150, etc., and the face plate 162 is always attached with airtightness maintained. Fixed and occluded.

The stage case 161 is attached to the inner peripheral surface of the stage case 161 via the Z-axis direction guide 165 so that the Z table 157 is movable along the Z-axis direction guide 165, thereby extending the entire sample stage 150 in the extending direction of the tilt shaft 156. Is supported so as to be movable in a predetermined direction orthogonal to the X-axis direction. At that time, the T base 155 protrudes along the X-axis direction from the opening of the contact-side end surface 163 of the stage case 161, and the base table surface on which the X table 154 and the like are supported is positioned outside the case. ing. As a result, the stage case 161 is in contact with the outer peripheral surface of the sample chamber housing 103 so that the contact side end surface 163 surrounds the sample exchange port 112 while the sample stage 150 is supported. An X table 154, a Y table 153, a rotation table 152, and a sample holder 151 disposed on the base table surface of the base 155 are introduced from the sample exchange port 112 into the center of the sample chamber 111, and the sample mounting surface of the sample holder 151 is introduced. the can be arranged at the intersection of the lower of the electron optical system 121, the optical axis Z _0.

  At that time, the stage case 161 is positioned so that the moving direction of the Z table 157 via the Z-axis direction guide 165 is parallel to the optical axis direction of the electron optical system 121 and the height direction of the sample chamber 111. Then, it is brought into close contact with the outer peripheral surface of the sample chamber casing 103. As a result, the sample of the sample holder 151 is controlled by moving or rotating the rotation table 152, Y table 153, X table 154, T base 155, and Z table 157 according to observation / analysis conditions by the electron optical system control unit 201. The mounting surface is horizontally moved, vertically moved, rotated, or tilted in the sample chamber 111, and the irradiation position and irradiation direction of the charged particle beam on the sample surface are adjusted.

  In addition, the stage case 161 is in close contact with the outer peripheral surface of the sample chamber housing 103 so that the contact-side end surface 163 surrounds the sample exchange port 112 in a state where the opening end surface 164 on the other end side is closed by the face plate 162. Together with the face plate 162, it functions as a sample exchange port cover 160 that seals the sample chamber 111 against the environmental atmosphere (atmosphere) in which the SEM 100 is disposed outside the apparatus housing 101.

When the contact-side end surface 163 of the stage case 161 is brought into close contact with the outer peripheral surface of the sample chamber housing 103, the stage case 161 is guided and supported by the guide support mechanism 170. In the illustrated example, the guide support mechanism 170 is attached to the apparatus casing 101 (sample chamber casing 103), and extends outside the casing along the opening direction of the sample exchange port 112 (in the illustrated example, the X-axis direction). The extending guide shaft 171 and an engaging portion 172 are integrally formed on the outer peripheral surface of the stage case 161 and are engaged with the guide shaft 171 so as to be movable along the extending direction. The guide support mechanism 170 abuts / separates the abutting side end surface 163 with respect to the sample exchange port 112 of the sample chamber housing 103, and the base table surface of the sample stage 150 is the optical axis of the electron optical system 121 in the sample chamber 111. as it moved forward and backward relative to the Z _0, for guiding and supporting the stage casing 161. Further, the guide support mechanism 170 allows the Z table 157 of the sample stage 150 to move the Z-axis direction guide 165 in a state where the contact side end surface 163 of the stage case 161 is in contact with the outer peripheral surface of the sample chamber housing 103. The contact posture of the stage case 161 with respect to the sample chamber housing 103 is defined so as to move along the optical axis direction of the electron optical system 121.

In the observation / analysis operation of the sample 110 using the SEM 100, the sample stage 150 supported by the stage case 161 is introduced / derived to / from the sample chamber 111 corresponding to the closing / opening of the sample exchange port 112. Specifically, when observing and analyzing the sample 110, the stage case 161 that also functions as the sample replacement port cover 160 is guided and supported in a state where the sample holder 151 on which the sample 110 is mounted is fixed to the rotation table 152. The sample stage 150 is introduced into the central portion of the sample chamber 111 by moving the contact side end surface 163 against the opening edge of the sample exchange port 112 of the sample chamber casing 103 by moving the sample stage using the sample holder 170. The sample mounting surface 151 is arranged so as to intersect the optical axis Z ₀ of the electron optical system 121 in the sample chamber 111. Then, with the stage case 161 in contact with the opening edge of the sample exchange port 112 of the sample chamber housing 103, the sample chamber 111 is evacuated to a vacuum state suitable for observation / analysis, so that The contact end surface 163 is closely attached to the opening edge of the sample exchange port 112 while maintaining airtightness, and the sample chamber 111 is isolated from the environmental atmosphere outside the apparatus housing 101. On the other hand, when the sample stage 150 is led out from the sample chamber 111 for sample exchange or the like, the sample chamber 111 in a vacuum state suitable for observation / analysis is set to a return pressure (not shown) including, for example, a valve. After returning the pressure to the atmospheric pressure using the mechanism, the stage case 161 is guided and moved along the guide shaft 171, and the sample stage 150 is led out from the sample exchange port 112, whereby the sample holder 151 is removed from the rotation table 152. Can be removed.

  By the way, in such observation / analysis work of the sample 110 using the SEM 100, when the work time is long, the sample being observed is moved relative to the target position due to the temperature change of the installation environment of the apparatus. Slow sample drift occurs.

In the SEM 100, as shown in FIG. 1 and FIG. 3 to be described later, the shape of the lens barrel 102 and the sample chamber housing 103 that touch the environmental atmosphere (atmosphere) in which the SEM 100 is installed is, for example, in the case of the lens barrel 102. In the case of the cylinder and the sample chamber housing 103, it is usually an axially symmetric housing shape such as a hollow quadrangular column. Therefore, even if the environmental temperature in which the SEM 100 is installed changes during long-time observation / analysis work, and the lens barrel 102 and the sample chamber housing 103 are thermally deformed, the respective cases have axially symmetric housing shapes. The symmetry axis itself of the cylindrical lens barrel 102 and the hollow quadrangular prism-shaped sample chamber casing 103 has a structure that is difficult to be displaced even under the influence of thermal deformation of the sample chamber casing 103. Further, the position of the optical axis Z ₀ of the electron optical system 121 in the lens barrel 102 and the sample chamber casing 103 is usually set as shown in FIG. The converging lens 123, the objective lens 124, and the scanning polarizer 125 are arranged in a part, and have an axially symmetrical structure facing each other across the symmetry axis of the lens barrel 102 and the sample chamber housing 103. Displacement due to thermal deformation of the chamber housing 103 is less likely to appear.

  On the other hand, the stage case 161 that also serves as the sample exchange port lid 160 of the sample exchange port 112 and supports the sample stage 150 has a hollow square column shape in which the shape of the hollow frame that is in contact with the environmental atmosphere where the SEM 100 is installed is axisymmetric. Even in the case of a cylindrical shape, the contact side end surface 163 on one end side in the axial direction becomes a fixed end in close contact with the sample chamber housing 103, whereas deformation is restricted, whereas the other end side The opening end surface 164 is a free end whose deformation is not restricted when viewed in relation to the contact side end surface 163 even when the face plate 162 is attached and fixed. Thermal deformation due to changes in

  FIG. 6 is a diagram schematically showing the form of the stage case when the environmental temperature decreases and the stage case undergoes thermal contraction during a long period of observation / analysis work, and FIG. FIG. 6B is a perspective view of the stage case.

  FIG. 7 is a diagram schematically showing the form of the stage case when the environmental temperature rises and changes during the long-time observation / analysis operation, and the stage case is expanded and thermally deformed. FIG. A side view of the stage case and FIG. 7B are perspective views of the stage case.

  The configuration of the stage case 161 that supports the sample stage 150 shown in FIGS. 6 and 7 is the same as the description of the configuration of the stage case 161 that supports the sample stage 150 shown in FIGS. Since it overlaps, the same code | symbol is attached | subjected about the same component and the description is abbreviate | omitted.

  As shown in FIG. 6, when the temperature of the environmental atmosphere where the SEM 100 is installed during the long observation / analysis operation is changed lower than the initial operation, the outer surface touches the environmental atmosphere as the sample exchange lid 160. The stage case 161 and the face plate 162 that are present are affected by the decrease in the environmental temperature, and are thermally deformed so as to contract with respect to the initial form of the work.

  Specifically, in the stage case 161 in which the contact-side end surface 163 on one end side is in contact with and closely contacted with the opening edge of the sample exchange port 112 of the sample chamber housing 103, the contraction heat deformation is a contact at the fixed end. It appears and appears on the opening end surface 164 side on the other end side which is the free end side with respect to the side end surface 163 side.

  Therefore, the shape of the rectangular frame that constitutes the stage case 161 and whose end surface shape is axisymmetric is that each peripheral surface portion of the frame that is a flat surface contracts, and the shape of the open end surface 164 on the free end side is recessed. Distortion and the size of the frame part on the opening end face 164 side contract with respect to the frame part on the contact side end face 163 side. Further, the face plate 162 that is in contact with the same environmental atmosphere is also contracted and deformed, and the flat square plate shape at the beginning of the work is recessed and distorted.

  Further, as shown in FIG. 7, when the temperature of the environmental atmosphere in which the SEM 100 is installed during the long observation / analysis operation is increased and changed from the beginning of the operation, the outer surface becomes the environmental atmosphere as the sample replacement lid 160. The touched stage case 161 and the face plate 162 are affected by the increase in the environmental temperature, and are thermally deformed so as to expand with respect to the original form of work.

  Specifically, in the stage case 161 in which the contact-side end surface 163 on one end side is in contact with and closely contacted with the opening edge of the sample exchange port 112 of the sample chamber housing 103, the expansion thermal deformation is a contact at the fixed end. It appears and appears on the opening end surface 164 side on the other end side which is the free end side with respect to the side end surface 163 side.

  Therefore, the form of the rectangular frame that constitutes the stage case 161 and whose end face shape is axisymmetric is that each peripheral surface portion of the flat frame body is inflated, and the form of the open end face 164 on the free end side is convex. Swelled and distorted, and the size of the frame on the opening end surface 164 side portion is larger than that on the contact end surface 163 side. Further, the face plate 162 that is in contact with the same environmental atmosphere is also expanded and deformed, and the flat plate-like form that was flat at the beginning of the work swells and distorts in a convex shape.

  As described above, when the environmental temperature is changed during the observation / analysis operation for a long time, the environmental temperature is lowered or increased, and the stage case 161 supporting the sample stage 150 is thermally deformed, the stage case 161 is deformed in the Z-axis direction. The sample stage 150 attached and supported via the guide 165 changes its arrangement posture in the sample chamber 111.

  Specifically, when the stage case 161 is affected by a decrease in the environmental temperature and, for example, as shown in FIG. 6, the sample stage 150 is deformed by contraction heat deformation, the stage case 161 is subjected to the contraction heat deformation of FIG. As shown in FIG. 4, the arrangement posture in the sample chamber 111 changes.

  FIG. 8 is an explanatory diagram of the state of the sample stage in the SEM in which the arrangement posture in the sample chamber has changed due to the contraction thermal deformation of the stage case.

  In the example shown in the drawing, the stage 150 is contracted and deformed as shown in FIG. 6 so that the sample stage 150 supported on the inner wall surface of the stage case 161 via the Z-axis direction guide 165 is movably supported. The introduction position in the sample chamber 111 on one end side of the T base 155 is pushed so as to shift to the back side of the sample chamber 111 from the beginning of the work. Further, the axial position of the hollow quadrangular prism frame forming the stage case 161 and the axial position of the tilt shaft 156 of the T base 155 are not in a coaxial relationship, and the T base 155 is more than the axial position of the stage case 161. In the case of the illustrated example in which the axis position of the tilt axis 156 is shifted upward, the sample stage 150 is rotated so that the arrangement position in the sample chamber 111 on one end side of the T base 155 is moved upward from the beginning of the work. Be moved.

  In addition, when the stage case 161 is affected by the increase in the environmental temperature and is expanded and deformed as shown in FIG. 7, for example, the sample stage 150 is omitted from illustration due to the expansion and heat deformation of the stage case 161. Contrary to the case of contraction heat deformation shown in FIG. 8, the arrangement posture in the sample chamber 111 changes.

  In this case, when the stage case 161 is expanded and thermally deformed as shown in FIG. 7, the sample stage 150 supported so as to be movable via the Z-axis direction guide 165 with respect to the inner wall surface of the stage case 161 is T The introduction position in the sample chamber 111 on one end side of the base 155 is drawn so as to be shifted to the front side of the sample chamber 111 from the beginning of the work. Further, the axial position of the hollow quadrangular prism frame forming the stage case 161 and the axial position of the tilt shaft 156 of the T base 155 are not in a coaxial relationship, and the T base 155 is more than the axial position of the stage case 161. In the case of the illustrated example in which the axis position of the tilt axis 156 is shifted upward, the sample stage 150 rotates so that the arrangement position in the sample chamber 111 on one end side of the T base 155 is moved downward from the beginning of the work. Be moved.

  Next, a description will be given of the mechanism of sample drift that occurs when the environmental temperature at which the SEM is installed changes during the observation / analysis operation and the stage case is thermally deformed.

  If the environmental temperature decreases or rises during long-time observation / analysis work, and the stage case 161 supporting the sample stage 150 is contracted or deformed by heat, as shown in FIG. 8, for example, the stage case The sample stage 150 supported so as to be movable with respect to 161 via the Z-axis direction guide 165 is affected by the thermal deformation of the stage case 161, and the arrangement posture in the sample chamber 111 changes.

As a result, the sample stage 150 is supported by the change in the environmental temperature, without changing to the moving position of the Y table 153, the X table 154, and the Z table 157 at the beginning of the observation / analysis work, and without changing the rotation position of the tilt shaft 156. If the stage case 161 is thermally deformed, the three-dimensional coordinate system (X ₀ , Y ₀ , Z ₀ ) with the optical axis Z ₀ of the electron optical system 121 as the z axis and the movement of the Z table of the sample stage 150 are moved. The predetermined relationship with the three-dimensional coordinate system (X, Y, Z) having the displacement direction as the z-axis will fluctuate before and after thermal deformation due to a change in the environmental temperature of the stage case 161. As a result, in observation / analysis work over a long period of time, the acquired image is placed at the target position, which is the original observation / analysis position on the sample according to the observation / analysis conditions, due to temperature changes in the installation environment of the device. On the other hand, sample drift occurs that moves.

  Therefore, in the SEM 100 according to the present embodiment, the occurrence of the sample drift due to the change in the environmental temperature where the SEM 100 is installed is measured using the measurement of the environmental temperature where the SEM 100 is installed or the case temperature of the device casing 101 of the SEM 100. Regardless of the measurement, based on the analyzed mechanism of the sample drift, the sample drift is measured with high accuracy by directly measuring the amount of thermal deformation generated in the device casing 101 of the SEM 100 due to the change of the environmental temperature. Drift correction means 210 for reducing sample drift due to temperature changes is provided.

  FIG. 3 is a configuration diagram of an example of drift correction means provided in the SEM according to the present embodiment.

  In describing the drift correction means 210 shown in FIG. 3, the components of the SEM 100 shown in FIGS. 1 and 2 will be described using the same reference numerals.

  The drift correction unit 210 includes a deformation amount measurement unit 211, a drift correction circuit 212, and a heating / cooling unit 213.

  The deformation amount measuring unit 211 directly measures the amount of thermal deformation generated in the apparatus housing 101 of the SEM 100 due to a change in environmental temperature. The deformation amount measuring means 211 supports the sample stage 150 based on the analyzed sample drift mechanism, and the orientation of the sample stage 150 in the sample chamber 111 is attached to the opening edge of the sample exchange port 112 of the sample chamber housing 103. And is provided in a stage case 161 that also functions as the sample exchange port lid 160. As the deformation amount measuring means 211, a detection element such as a strain gauge or a displacement sensor is used to measure the degree of contraction thermal deformation or expansion thermal deformation of the stage case 161 due to a change in environmental temperature, that is, the deformation amount of the stage case 161. Used.

  In the illustrated example, a strain gauge 214 is used as the deformation amount measuring unit 211. The strain gauge 214 is related to the axial direction of the stage case 161 formed of a hollow frame, and is arranged at an axial position away from the contact-side end surface 163 on one end side and close to the opening end surface 164 on the other end side. This axial position also includes a face plate 162 attached and fixed to the open end face 164. This is because the contact-side end surface 163 on one end side is brought into contact with and intimate contact with the sample chamber housing 103 and becomes a fixed end, whereas the opening end surface 164 on the other end side is fixed with a face plate 162 attached thereto. However, when viewed in relation to the abutting side end surface 163, the deformation becomes a free end which is not restricted, and as shown in FIGS. 6 and 7, the thermal deformation due to the change of the environmental temperature becomes apparent.

  In addition, in the illustrated example, the strain gauge 214 is disposed on the corner peripheral wall portion of the stage case 161 in which the hollow frame is formed of a hollow quadrangular column. This is because the strain change of each of the two adjacent surfaces of the strain gauge 214 is detected when the distortion of the corner peripheral wall portion is detected, rather than when the strain generated on one of the peripheral surfaces of the stage case 161 due to thermal deformation is detected. This is because the thermal deformation of the stage case 161 can be detected with high accuracy. A detection signal output from the strain gauge 214 is input to the amplifier 215, amplified by the amplifier 215, and supplied to the drift correction circuit 212.

  Based on the detection signal from the strain gauge 214, the drift correction circuit 212 supports the current corner peripheral wall, that is, the sample stage 150, based on the magnitude of distortion of the corner peripheral wall of the input stage case 161. A control signal is generated for the heating / cooling means 213 that cancels the distortion caused by thermal deformation of the stage case 161 functioning as the sample exchange port cover 160 due to a change in environmental temperature, and is sent to the heating / cooling means drive circuit 216. Supply. The heating / cooling means driving circuit 216 drives the heating / cooling means 213 based on the control signal supplied from the drift correction circuit 212.

  The heating / cooling means 213 is provided on the outer surface of the stage case 161 and / or the face plate 162 that supports the sample stage 150, and the sample stage 150 that also functions as the sample exchange port cover 160 with the face plate 162 attached and fixed. The supporting stage case 161 is heated or cooled to reduce distortion due to thermal deformation that occurs in the stage case 161 and the face plate 162 based on a change in environmental temperature. As the heating / cooling means 213, for example, a heating / cooling device using a thermoelectric element such as a Peltier element is used.

  In the illustrated example, as the heating / cooling means 213, a plurality of (three in the illustrated example) thin-plate heating / cooling devices 217 using Peltier elements are used. The plurality of heaters / coolers 217 are positioned at the center of the outer surface of the face plate 162 closely fixed to the opening end face 164 of the stage case 161 in the height direction of the face plate 162 corresponding to the optical axis direction of the electron optical system 121. Are arranged side by side in the horizontal direction. Here, the heating / cooling device 217 is provided on the face plate 162 because the face plate 162 does not support the sample stage 150 via the Z-axis direction guide 165 rather than the stage case 161 in contact with the same environmental atmosphere. First, the heating effect or the cooling effect by the heating / cooling means 213 is likely to appear. As a result, the heating / cooling means 213 is heated or cooled by the heating / cooling means 213 for the entire sample exchange port lid 160 composed of the stage case 161 and the face plate 162. This is because it can be efficiently performed by heating or cooling the face plate 162. The reason why the heating / cooling device 217 is provided on the outer surface of the face plate 162 is to prevent the heating effect or cooling effect of the heating / cooling device 217 from directly diffusing into the sample chamber 111.

  Next, in detail of the control configuration of the heating / cooling unit 213 by the drift correction circuit 212 described above, the relationship between the sample drift of the SEM 100 and the distortion of the stage case 161 is illustrated in the SEM 100 according to the present embodiment. 4 will be described.

  FIG. 4 is a verification graph of the relationship between the drift amount of the sample drift and the strain amount generated in the stage case.

  In the verification, the environmental temperature of the environment in which the SEM 100 is installed is separately controlled so as to maintain a constant temperature, and the heating / cooling unit 213 continues to heat the face plate 162 integrated with the stage case 161 to perform observation / analysis work time. The installation environment of the SEM 100 in which the environmental temperature simply increases with the passage of time was simulated. At that time, the temperature of the face plate 162 at the time 0 when the face plate 162 starts to be heated by the heating / cooling means 213, that is, a constant environmental temperature, is that the face plate 162 is contracted by thermal deformation and the plate surface form is flat. It was set as the predetermined environmental temperature which is dented and distorted.

  Therefore, the time on the horizontal axis of the graph in FIG. 4 represents the temperature rise change of the face plate 162 integrated with the stage case 161 according to the heating time by the heating / cooling device 217 as the heating / cooling means 213, that is, the environmental temperature rise. This corresponds to a change represented by a time parameter.

  The drift amount shown on the left vertical axis of the graph is based on the target position on the sample 110 mounted on the sample table 150, and the control of the electron optical system 121 and the sample stage 150 set corresponding to the target position. The amount of deviation from the irradiation position on the sample 110 that is actually irradiated with the primary electron beam 120 is shown. A value of 0 indicates that the target position and the irradiation position on the sample 110 of the primary electron beam 120 are correct.・ Negative slip direction.

  The drift amount shown on the right vertical axis of the graph indicates the magnitude of the detection signal supplied from the strain gauge 214 as the deformation amount measuring means 211 to the drift correction circuit 212 via the amplifier 215.

  As shown in FIG. 4, by heating the face plate 162 integral with the stage case 161 by the heater / cooler 217, the heating time elapses, that is, the temperature rises with respect to the initial temperature of the face plate 162, and before heating starts. The concave and distorted deformation of the face plate 162 and the stage case 161 that have been dented and distorted in a predetermined state due to the contraction thermal deformation due to the predetermined environmental temperature is gradually reduced. At this time, the magnitude of the detection signal supplied from the strain gauge 214 to the drift correction circuit 212 via the amplifier 215 and the drift amount of the sample drift gradually decrease.

  Further, by continuing heating of the face plate 162 integrated with the stage case 161 by the heater / cooler 217, the temperature of the face plate 162 further rises from a predetermined environmental temperature, and the drift amount of the face plate 162 and the stage case 161 is zero. Then, after the form of the face plate 162 corresponding to 0, this drift amount starts to expand and thermally deform the face plate 162 and the stage case 161, and the form of the plate surface bulges into a convex shape with respect to the flat state and starts to be distorted. And the deformation | transformation which bulged and distorted to the convex shape increases with progress of the heating time, ie, the further temperature rise of the face plate 162. FIG. At this time, the magnitude of the detection signal supplied from the strain gauge 214 to the drift correction circuit 212 via the amplifier 215 is gradually decreased, and the drift amount of the sample drift is in the opposite direction with respect to the drift amount of 0 as a reference. It gradually increases in the negative direction in the figure.

  As a result, the drift amount and the detection output from the strain gauge 214 both increase and decrease monotonously as the continuous heating time by the heater / cooler 217 increases, in other words, as the environmental temperature in which the SEM 100 is installed increases. I understand that.

  As a result, as shown in FIG. 6 and FIG. 7, the deformation form due to the contraction thermal deformation and the expansion thermal deformation of the stage case 161 that supports the sample stage 150, regardless of the environmental temperature change where the SEM 100 is installed, If the face plate 162 and the stage case 161 can be heated or cooled by the heating / cooling device 217 as the heating / cooling means 213 and can be maintained in a certain deformation form during the observation / analysis operation, the stage case 161 in the sample chamber 111 is maintained. It can be understood that the arrangement posture of the sample stage 150 can be kept constant, and the occurrence of sample drift due to a change in environmental temperature can be reduced.

  Therefore, in the drift correction circuit 212 of the drift correction means 210 according to the present embodiment, for example, the heating / cooling device 217 is next set based on the detection signal supplied from the strain gauge 214 to the drift correction circuit 212 via the amplifier 215. The operation is controlled as described to reduce the occurrence of sample drift due to a change in environmental temperature.

  The drift correction circuit 212 takes in the distortion immediately before the start of the observation / analysis work using the SEM 100, that is, the magnitude of the detection signal supplied from the strain gauge 214 via the amplifier 215 immediately before the start, and sets and stores it as a reference value. .

  When the observation / analysis operation using the SEM 100 is started, the drift correction circuit 212 sequentially captures the detection signal supplied from the strain gauge 214 via the amplifier 215, and the magnitude and reference of the captured detection signal. Compare the value. Based on the comparison result, in the case of the example shown in FIG. 4, when the magnitude of the detection signal is larger than the reference value, the heating / cooling means drive circuit 216 sets the magnitude of the detection signal to the reference value. The heating / cooling means driving circuit 216 heats the heating / cooling device 217 based on this control signal. On the other hand, when the magnitude of the detection signal is smaller than the reference value, a control signal for raising the magnitude of the detection signal so as to approach the reference value is output to the heating / cooling means driving circuit 216, and heating is performed. The cooling means driving circuit 216 cools the heating / cooling device 217 based on this control signal.

  In the above example, the distortion immediately before the start of the observation / analysis work using the SEM 100, that is, the magnitude of the detection signal supplied from the strain gauge 214 via the amplifier 215 immediately before the start is used as the reference value. Observation and analysis work can be performed quickly after the start instruction. The reference value is not limited to the detection output from the strain gauge 214 immediately before the start of the observation / analysis work using the SEM 100, but the start instruction of the observation / analysis work and the start of the actual observation / analysis work are started. However, it is possible to set the magnitude of an arbitrary detection signal of the strain gauge 214 within a range that can be corrected by the heater / cooler 217. In this case, depending on the magnitude of the detection signal set as the reference value, the heating / cooling device 217 can be replaced with only a heating device or a cooling device.

  As described above, according to the SEM 100 according to the present embodiment, the stage stage 150 is supported by the temperature change of the environmental atmosphere in which the SEM 100 is installed, and is affected by the temperature change in contact with the environmental atmosphere. By directly measuring the amount of thermal deformation generated in 161, the sample drift caused in the charged particle beam device due to the temperature change in the installation environment can be measured with high accuracy, and the drift due to the temperature change in the installation environment can be reduced.

  Note that, regarding the SEM according to the present embodiment, the specific configuration of the sample stage 150 itself, the specific configuration of the stage case 161 that supports the sample stage 150, and the like are specific to the SEM 100 shown in FIG. The configuration is not limited. Therefore, even when the specific configuration of the sample stage 150 and the stage case 161 is different from that of the SEM 100 shown in FIG. 1, the deformation amount measurement for measuring the amount of thermal deformation generated in the stage case 161 that supports the sample stage 150. The location of the means 211 and the location of the heating / cooling means 213 that counteracts the sample drift by suppressing the deformation due to the temperature change of the installation environment of the stage case 161 are subject to sample drift caused by changes in the environmental temperature by experiment, calculation, etc. Appropriately select a housing location that can effectively cancel the thermal deformation of the stage case 161 that causes it, and a housing location that satisfies the relationship in which the distortion of the stage case 161 changes monotonously with respect to the sample drift due to a change in environmental temperature. It is possible to cope with it.

  The specific configuration of the drift correction unit 210 including the deformation amount measurement unit 211, the drift correction circuit 212, and the heating / cooling unit 213 is also limited to the configuration of the drift correction unit shown in FIG. It is not a thing.

  FIG. 5 is a configuration diagram of another example of the drift correction means provided in the SEM according to the present embodiment.

  In the configuration of the drift correction means 210 shown in FIG. 5, the components of the SEM 100 shown in FIGS. 1 and 2 will be described using the same reference numerals.

  The thermal deformation of the stage case 161 supporting the sample stage 150 in the sample chamber 111, to which the face plate 162 is integrally fixed, is caused by the flow of the ambient atmosphere (atmosphere) around the stage case 161 and the face plate 162, the external device, and the SEM. If the temperature changes depending on the heat source of the operator or the like and the influence is great, the thermal deformation behavior may be different at each peripheral surface portion of the stage case 161 or at each location on the face plate 162.

  Therefore, in the drift correction unit 210 according to the present embodiment, for example, as shown in FIG. 5, the deformation amount measurement unit 211 is provided on each corner peripheral wall portion of the stage case 161 in which the hollow frame is formed of a hollow quadrangular column. The strain gauges 214 are attached, and the heating / cooling means 213 is configured such that nine heating / cooling devices 217 are attached to the outer surface of the face plate 162.

  The number of strain gauges 214 attached to the stage case 161 and the arrangement thereof are not limited to four as long as it is plural, and the plurality of strain gauges 214 are evenly distributed around the outer periphery of the stage case 161. It does not matter as long as the arrangement is such that the distortion of each peripheral surface portion corresponding to the stage case 161 can be detected under the same conditions. Similarly, the number of heaters / coolers 217 to be attached and the number of the heaters / coolers 217 are not limited to nine as long as they are plural, and a plurality of heaters / coolers 217 are evenly arranged on the face plate 162. It suffices if each of the corresponding face plate portions has an arrangement configuration capable of exerting the same heating / cooling effect under the same conditions.

  On the other hand, the drift correction circuit 212 supports the current corner peripheral wall portion, that is, the sample stage 150 while sequentially receiving the detection signals from the respective strain gauges 214 (214Lu, 214Ld, 214Ru, 214Rd), and also the sample exchange lid. A control signal is generated for each heating / cooling device 217 (217-11 to 217-33) that cancels distortion caused by thermal deformation due to a change in environmental temperature of the stage case 161 functioning as 160, and is heated. Supply to the cooling means drive circuit 216 The heating / cooling means driving circuit 216 drives each of the heating / cooling devices 217 (217-11 to 217-33) based on the control signal supplied from the drift correction circuit 212.

  In the illustrated example, for example, the drift correction circuit 212 is strained immediately before the start of the observation / analysis operation using the SEM 100, that is, from each strain gauge 214 (214Lu, 214Ld, 214Ru, 214Rd) via the amplifier 215 immediately before the start. The magnitude of the supplied detection signal is captured. In addition, regarding the control of the heating / cooling device 217-11, the detection output from the strain gauge 214Lu, and regarding the control of the heating / cooling device 217-12, the detection output from the strain gauge 214Lu and the detection output from the strain gauge 214Ru. The detection output and the average value, the detection output from the strain gauge 214Ru for the control of the heating / cooling device 217-13, and the detection output and the strain gauge from the strain gauge 214Lu for the control of the heating / cooling device 217-21. As for the detection output and average value from 214Ld and the control of the heater / cooler 217-22, the average value of the detection output from each strain gauge 214Lu, 214Ld, 214Ru, 214Rd is controlled by the heater / cooler 217-23. , The detection output from the strain gauge 214Ru, the detection output from the strain gauge 214Rd and the average value, and the control of the heater / cooler 217-31, the strain gauge 14Ld, the detection output from the strain gauge 214Ld, the detection output from the strain gauge 214Rd, and the average value for the control of the heating / cooling device 217-32, and the control output of the heating / cooling device 217-33. The detection output from the strain gauge 214Rd is set and stored as a reference value.

  When the observation / analysis operation using the SEM 100 is started, the drift correction circuit 212 sequentially captures detection signals supplied from the strain gauges 214 (214Lu, 214Ld, 214Ru, 214Rd) via the amplifier 215, respectively. The comparison values for the respective reference values are calculated in the same manner based on the acquired detection signals. Then, for each heating / cooling device 217 (217-11 to 217-33), the corresponding reference value is compared with the calculated comparison value, and based on the comparison result, the corresponding heating / cooling device 217 (217-) is compared. 11 to 217-33) is output to the heating / cooling means driving circuit 216, and the driving is controlled for each heating / cooling device 217 (217-11 to 217-33).

  As described above, in the drift correction unit 210 according to the present embodiment, a plurality of heating / cooling devices 217 (217-11 to 217-33) are attached to the stage case 161, whereby the stage case 161 and the face plate 162 are complicatedly deformed. It becomes possible to recognize the behavior, and by attaching a plurality of heating / cooling devices 217 (217-11 to 217-33) to the outer surface of the face plate 162, the response of drift correction is improved, and arbitrary heating / cooling By heating and cooling the vessel 217 (217-mn), the face plate 162 can be adapted to partial thermal deformation. As a result, the drift due to the complicated thermal deformation behavior of the stage case 161 can also be corrected.

  As described above, the SEM 100 as an embodiment of the charged particle beam apparatus according to the present invention is configured, but the present invention can also be applied to a charged particle beam apparatus other than the SEM. In other words, even if the stage case that supports the sample stage is in direct contact with the environmental atmosphere or the stage case is not in direct contact with the environmental atmosphere, the influence of temperature changes in the environmental atmosphere during observation and analysis work If the charged particle beam apparatus is easily received, a configuration that reduces the occurrence of sample drift due to a change in environmental temperature by a drift correction unit having a deformation amount measurement unit, a drift correction circuit, and a heating / cooling unit is applicable.

100 SEM, 101 device housing, 102 lens barrel, 103 sample chamber housing,
110 sample, 111 sample chamber, 112 sample exchange port, 120 primary electron beam,
121 electron optical system, 122 electron gun, 123 converging lens,
124 objective lens, 125 scanning polarizer, 130 secondary electrons,
131 secondary electron detector, 140 characteristic X-ray (secondary particle),
141 EDX detector (secondary particle detector), 150 sample stage,
151 Sample holder, 152 Rotation table, 153 Y table,
154 X table, 155 T base, 156 tilt axis,
157 Z table, 160 Sample exchange mouthpiece, 161 Stage case,
162 face plate, 163 abutting side end face, 164 opening end face,
165 Z-axis direction guide, 170 Guide support mechanism, 171 Guide shaft,
172 engagement unit, 201 electron optical system control unit, 202 image generation unit,
203 observation image display unit, 205 EDX processing unit, 206 analysis image display unit,
210 drift correcting means, 211 deformation amount measuring means,
212 drift correction circuit, 213 heating / cooling means, 214 strain gauge,
215 amplifier, 216 heating / cooling means driving circuit, 217 heating / cooling device.

Claims (3)

A sample chamber for irradiating the sample with a charged particle beam;
A sample stage on which a sample to be irradiated with a charged particle beam is mounted;
A charge comprising an inner surface facing the sample chamber and an outer surface facing an external environmental atmosphere, and a stage case that supports the sample stage and places a sample mounted on the sample stage in the sample chamber In particle beam equipment,
Deformation amount measuring means for measuring the deformation amount of the stage case;
Temperature adjusting means for heating and / or cooling the outer surface of the stage case;
Based on the deformation amount measured by the deformation amount measuring means, the temperature adjusting means is operated and controlled so that the irradiation position of the charged particle beam on the sample mounted on the sample stage does not move due to the temperature change of the environmental atmosphere. A charged particle beam device comprising a control means.   The charged particle beam apparatus according to claim 1, wherein the deformation amount measuring unit is a strain measuring unit that detects a strain generated in the stage case. The temperature adjusting means is a heating / cooling means for heating and cooling the outer surface of the stage case,
The control means, based on the deformation amount measured by the deformation amount measurement means, when the stage case is expanded and thermally deformed due to a temperature change of the environmental atmosphere, the heating / cooling means cools the stage case, 3. The charged particle beam apparatus according to claim 1, wherein the stage case is heated by the heating / cooling unit when the stage case is contracted and thermally deformed by a temperature change of an environmental atmosphere. 4.

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