Sample piece creation device and sample piece creation method

Abstract

The purpose of the present invention is to provide a sample piece creation technology capable of improving throughput of a sample manufacturing process by shortening a processing time for creating a sample piece. A sample piece creation device according to the present invention comprises a tweezers unit that grips a sample piece by a first tweezers arm and a second tweezers arm. The second tweezers arm is configured such that rigidity thereof in a direction of being driven by a drive mechanism is higher than that of the first tweezers arm. The tweezers unit is driven so that an action of pressing the second tweezers arm toward the first tweezers arm is exerted (see fig. 16).

Description

Sample piece preparation device and sample piece preparation method

[0001] The present invention relates to a technique for preparing a specimen.

[0002] In recent years, the semiconductor field has seen advances in miniaturization and high integration of devices, leading to the creation of complex circuits, such as three-dimensional circuits. To detect circuit defects during the manufacturing process, a portion of the circuit is cut out as a sample and its cross section is observed using a transmission electron microscope. The sample is then thinned at the observation site where the transmission electron microscope irradiates the electrons for observation.

[0003] Patent Document 1 describes a method for preparing a sample piece, in which a surface of an object to be observed is subjected to laser beam processing or ion beam processing to prepare a sample piece having at least one support portion inside a groove, and the sample piece is then grasped with tweezers and broken off so as to break the support portion.

[0004] Japanese Patent Application Laid-Open No. 2017-003579

[0005] In the semiconductor industry, improving throughput by shortening the time per inspection is important. In the above-mentioned conventional techniques, laser beam processing or ion beam processing requires long processing times, making it difficult to improve throughput. To improve throughput, the tweezers must be operated faster. Simply increasing the speed of the operation increases the deflection of the tweezers during snapping. Therefore, to prevent the tweezers from contacting parts other than the sample piece, it is necessary to widen the grooves in which the sample piece is formed. Grooves require a larger amount of processing compared to the support portion, resulting in a longer processing time, making it difficult to improve throughput. If attempts are made to reduce the amount of groove processing by increasing the rigidity of the tweezers to suppress deflection, the thickness of the tweezers increases, so sufficient margin for the grooves must be ensured.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a sample piece preparation technology that can improve the throughput of the sample manufacturing process by shortening the processing time required to prepare the sample piece.

[0007] The sample piece preparation device of the present invention includes a tweezers unit that grasps a sample piece using a first tweezers arm and a second tweezers arm, the second tweezers arm being configured to have higher rigidity in the direction driven by the drive mechanism than the first tweezers arm, and the tweezers unit is driven so as to exert the effect of pressing the second tweezers arm toward the first tweezers arm.

[0008] The present invention provides a sample piece preparation device that can improve the throughput of the sample production process by shortening the processing time required to prepare the sample piece. Other objects, configurations, advantages, etc. of the present invention will become clear from the following description of the embodiments.

[0009] 10 shows a configuration diagram of a thin sample observation system equipped with a sample piece preparation device according to embodiment 1. A schematic diagram of a charged particle beam instrument 102 according to an embodiment. An enlarged perspective view of a wafer processing unit 213. A top view of the wafer processing unit 213. An α-α cross-sectional view of the wafer processing unit 213 shown in FIG. 4. A perspective view of a mechanical unit 601 equipped in a sample piece preparation device 103. A configuration diagram of an optical interference microscope system 610 is shown. An enlarged perspective view of tweezers 605 is shown. An enlarged perspective view of a tweezers tip 805 is shown. A view of the tweezers tip 805 as viewed from the arrow. A β-β cross-sectional view of FIG. 10 when a sample piece is gripped is shown. A top view of the tweezers tip 805 and the sample piece processing groove 304 as viewed from the -Y axis direction is shown. A flowchart explaining the procedure by which the mechanical unit 601 extracts sample piece B. The tweezers tip 805 and sample piece B approach each other. The tweezers tip 805 and sample piece B are shown gripping sample piece B. 17 shows how sample piece B is broken off by translational movement of mechanism unit 601. 18 shows how sample piece B is broken off by rotational movement of mechanism unit 601. 19 shows a two-dimensional cross-sectional view passing through support unit 303 when the breaking of the sample piece shown in FIG. 17 is viewed from the -X axis direction. 20 shows how sample piece B is lifted out by mechanism unit 601.

[0010] 1 shows a configuration diagram of a thin sample observation system equipped with a sample preparation device according to embodiment 1 of the present invention. The thin sample observation system 100 comprises a plurality (n1 units) of charged particle beam devices 102, a plurality (n2 units) of sample preparation devices 103, and a plurality (n3 units) of transmission electron microscopes 104.

[0011] The thin sample observation system 100 forms a sample piece B on the surface of the wafer A by performing laser beam processing or ion beam processing on the wafer A using a charged particle beam device 102. The wafer A including the sample piece B is then transferred to a sample piece preparation device 103. The sample piece preparation device 103 extracts the sample piece B from the wafer A. The sample piece B extracted from the wafer A is transferred to a transmission electron microscope 104. The transmission electron microscope 104 measures the sample piece B.

[0012] In the following description, the X-axis, Y-axis, and Z-axis directions are perpendicular to each other in three-dimensional space. The Y-axis direction is the vertical direction of the device. The X-axis and Z-axis directions are two directions horizontal to the device.

[0013] 2 is a schematic diagram of a charged particle beam device 102 according to an embodiment. The charged particle beam device 102 includes a focused ion beam column 201, a sample chamber 202, a secondary charged particle detector 203, an electron beam column 204, a first driving mechanism 205, a stage 206, a second driving mechanism 207, a gas supply unit 208, and a gas ion beam column 209.

[0014] A stage 206 having a first drive mechanism 205 and a second drive mechanism 207 is installed inside the sample chamber 202. A wafer A to be observed is fixed on the stage 206. An electron beam column 204, a gas ion beam column 209, a secondary charged particle detector 203, and a gas supply unit 208 are installed inside the sample chamber 202 from different directions and tilted at a predetermined angle with respect to the Y-axis direction. A focused ion beam column 201 is installed inside the sample chamber 202 along the Y-axis direction. The electron beam column 204, the focused ion beam column 201, and the gas ion beam column 209 are installed so that their optical axes intersect at a predetermined position on the top surface of the wafer A fixed on the top of the stage 206.

[0015] The positions of the electron beam column 204, the focused ion beam column 201, and the gas ion beam column 209 may be interchanged. For example, either the electron beam column 204 or the gas ion beam column 209 may be installed along the Y-axis direction, and the focused ion beam column 201 may be installed at a predetermined angle with respect to the Y-axis direction.

[0016] The first driving mechanism 205 can rotate the stage 206 around the X-axis. The second driving mechanism 207 can translate the stage 206 in the X-, Y-, and Z-axis directions, and can rotate the stage 206 around the Y-axis. By using the first driving mechanism 205 and the second driving mechanism 207, processing can be performed on the surface of the wafer A from a predetermined position and angle.

[0017] The electron beam column 204 can irradiate an electron beam 210, the focused ion beam column 201 can irradiate a focused ion beam 211, and the gas ion beam column 209 can irradiate a gas ion beam 212 onto an object within a predetermined irradiation region inside the sample chamber 202. The secondary charged particle detector 203 can detect secondary charged particles (secondary electrons and secondary ions) generated from the object by irradiation with the electron beam 210, the focused ion beam 211, or the gas ion beam 212. The gas supply unit 208 can supply an etching gas, a deposition gas, etc. to the irradiation object.

[0018] The charged particle beam device 102 processes the surface of a wafer A made of a semiconductor such as silicon, and forms an observation surface of a desired thickness on the specimen B suitable for transmission observation by the transmission electron microscope 104. By irradiating a wafer processing portion 213 of the wafer A fixed to the stage 206 with a focused ion beam 211 while scanning it, imaging of the irradiated portion, various processing by sputtering (drilling, trimming, etc.), formation of a deposition film, etc. are performed.

[0019] The stage 206 is moved in translation in the X-axis, Y-axis, and Z-axis directions and rotated around the X-axis and Y-axis by a first driving mechanism 205 and a second driving mechanism 207. This allows the wafer A to be processed by irradiating it with a focused ion beam 211 from any angle.

[0020] The charged particle beam device 102 irradiates the wafer A with a focused ion beam 211 or an electron beam 210 while scanning it, and acquires an image of the surface. The image of the irradiated object is an image acquired by a scanning ion microscope, a scanning electron microscope, an absorption current method, or the like. An image acquired by a scanning ion microscope or a scanning electron microscope is an image based on secondary charged particles (secondary electrons or secondary ions) generated from the irradiated object by irradiation with the focused ion beam 211 or the electron beam 210. An image acquired by an absorption current method is an image based on the inflow current of the charged particle beam flowing into the irradiated object (or the absorption current of the charged particle beam absorbed by the irradiated object).

[0021] The etching gas selectively promotes etching of the irradiated object by the focused ion beam 211 depending on the material of the irradiated object. The deposition gas forms a deposition film of deposits of metal, insulator, etc. on the surface of the irradiated object. The deposition film is formed by solid components decomposed from the deposition gas supplied from a gas supply unit and deposited on the surface of the irradiated object when the charged particle beam is irradiated.

[0022] 3 is an enlarged perspective view of the wafer processing section 213. The wafer surface 301 is perpendicular to the Y-axis direction, and the longitudinal direction of the sample piece B is the X-axis direction. The wafer processing section 213 comprises the sample piece B, the wafer surface 301, an observation surface 302, a support portion 303, and a sample piece processing groove 304. In the wafer processing section 213, a focused ion beam 211 is irradiated onto the wafer surface 301, thereby removing the periphery of the sample piece B to form the sample piece processing groove 304, and processing the wafer A and the sample piece B into a shape in which they are interconnected via at least one support portion 303. The sample piece B has an observation surface 302 formed at an arbitrary measurement location, and the observation surface 302 can be measured using a transmission electron microscope.

[0023] Fig. 4 is a top view of the wafer processing unit 213. Fig. 5 is an α-α cross-sectional view of the wafer processing unit 213 shown in Fig. 4. In the figure, the longitudinal direction of the sample piece B is the X-axis direction, the wafer surface 301 is perpendicular to the Y-axis direction, direction D2 is the Y-axis direction, and directions D1 and D3 are directions inclined at angles θ1 and θ2 around the X-axis with respect to the Z-axis direction.

[0024] The procedure for processing the wafer processing portion 213 will be described. First, the wafer processing portion 213 is irradiated with a focused ion beam 211 from the direction D2 by the charged particle beam device 102 to form a sample piece processing groove 304. The direction D1 and direction D3 sides of the sample piece processing groove 304 have inclined surfaces 502 at angles θ1 and θ3, respectively, around the X axis with respect to the wafer surface 301.

[0025] Next, the wafer processing portion 213 is irradiated with a focused ion beam 211 from the direction D1 or D3 by the charged particle beam device 102, and the periphery of the sample piece lower portion 501 and the support portion 303 is removed. As a result, a sample piece B having the support portion 303 is formed.

[0026] Finally, the sample B is irradiated with a focused ion beam 211 from the direction D2 by the charged particle beam device 102, thereby forming an observation surface 302 for observation using a transmission electron microscope. The wafer A including the sample B processed by the above procedure is transferred to the sample preparation device 103.

[0027] In this embodiment, the inclined surface 502 of the sample piece processing groove 304 does not change angle from the sample surface to the bottom, but may have a stepped, tapered or curved shape. In this embodiment, the support part 303 has a uniform beam shape with no change in cross-sectional area in the X-axis direction, but may have a constricted shape in the X-axis direction to make it easier to break. In this processing procedure, the sample piece processing groove 304 is formed before the observation surface 302 is formed, but the sample piece processing groove 304 may also be formed after the observation surface 302 is formed.

[0028] 6 is a perspective view of a mechanism 601 provided in the sample piece preparation device 103. The mechanism 601 (first drive mechanism) includes a gantry 602, a support 603, a tweezers support unit 604, tweezers 605, a wafer suction chuck 606, a horizontal XZ stage 607, a surface plate 608, a vertical Y stage 609, an optical interference microscope system 610, a rotation stage 611, a mesh holder 612, and a wafer A. The horizontal XZ stage 607 and the rotation stage 611 are mounted on the surface plate 608. The wafer suction chuck 606 is mounted on the rotation stage 611. A mesh holder 612 for storing the sample piece is mounted on the horizontal XZ stage 607. The gantry 602 is mounted on the surface plate 608 via a support 603. The tweezers 605 are mounted on the gantry 602 via a tweezers support unit 604, and the optical interference microscope system 610 is mounted on the vertical Y stage 609.

[0029] The computer 620 is a computer that controls each part of the test piece preparation device 103. The computer 620 may be configured as a part of the test piece preparation device 103, or may be configured as another device (e.g., a control device arranged outside the test piece preparation device 103, a computer configured as a part of the thin section sample observation system 10, etc.).

[0030] After the wafer A including the sample piece B transported from the charged particle beam device 102 is fixed to the wafer suction chuck 606, the sample piece B, tweezers 605, and mesh holder 612 are aligned using the horizontal XZ stage 607, vertical Y stage 609, and tweezers 605, and the sample piece B is removed and stored.

[0031] 7 shows a configuration diagram of an optical interference microscope system 610. The optical interference microscope system 610 includes an observation lens barrel 701, a light source lens barrel 712, and a vertical Y stage 609. The observation lens barrel 701 and the light source lens barrel 712 are integrally connected perpendicularly to each other. The longitudinal direction of the light source lens barrel 712 is the X-axis direction, and the longitudinal direction of the observation lens barrel 701 is the Y-axis direction.

[0032] The light source barrel 712 includes a light source 711 and a filter 710. The light source 711 is a white light source. The filter 710 is a wavelength filter such as a bandpass filter and a polarization filter.

[0033] The observation lens barrel 701 comprises an observation camera 702 , an imaging lens 703 , a first beam splitter 704 and a second beam splitter 707 , a reflecting mirror 705 , a first objective lens 708 and a second objective lens 706 , and a position adjustment camera 709 .

[0034] The first beam splitter 704 is installed at a position where the central axes of the light source barrel 712 and the observation barrel 701 intersect. The first beam splitter 704 reflects the illumination light that travels from the light source 711 through the filter 710 toward a first end 701 a of the observation barrel 701 that is closer to the observation target (i.e., toward the first objective lens 708).

[0035] The first beam splitter 704 transmits the combined light of the reflected light L2 from the second beam splitter 707 (described later) and the reflected light L1 from the object of observation toward the second end 701b, which is the end of the observation tube 701 that is closer to the observation camera 702.

[0036] The second beam splitter 707 is installed between the first beam splitter 704 and the first objective lens 708. The second beam splitter 707 splits the illumination light L3 from the first beam splitter 704 into a first direction of the central axis of the observation lens barrel 701 and a second direction perpendicular to the central axis of the observation lens barrel 701. The first direction is the Y-axis direction toward the first objective lens 708, which will be described later. The second direction is the X-axis direction toward the second objective lens 706, which will be described later.

[0037] The second beam splitter 707 causes the combined light obtained by superimposing the reflected light L1 from the observation object (described later) and the reflected light L2 from the reflecting mirror 705 to travel toward the second end 701b of the observation lens barrel 701. The interference state of the combined light changes depending on the optical path difference between the reflected light L1 from the observation object and the reflected light L2 from the reflecting mirror 705.

[0038] The first objective lens 708 is installed at the first end 701 a of the observation lens barrel 701. The first objective lens 708 focuses the illumination light L3 traveling (transmitting) in the first direction from the second beam splitter 707 onto the observation object (wafer A, tweezers 605, and mesh holder 612).

[0039] The second objective lens 706 is installed away from the second beam splitter 707 in the second direction. The second objective lens 706 focuses the illumination light L3 traveling (reflected) in the second direction from the second beam splitter 707 onto the reflecting mirror 705.

[0040] The reflecting mirror 705 is disposed away from the second objective lens 706 in the second direction. A reference surface 705a, which is a surface formed smoothly with a predetermined accuracy, is disposed on the reflecting mirror 705. The reflecting mirror 705 reflects the illumination light L3 from the second objective lens 706 toward the second beam splitter 707 by the reference surface 705a.

[0041] The imaging lens 703 is installed between the first beam splitter 704 and the observation camera 702. The imaging lens 703 forms an image of the interference fringes by focusing the combined light from the first beam splitter 704.

[0042] The observation camera 702 is installed at the second end 701b of the observation lens barrel 701. The observation camera 702 captures an interference fringe of the combined light formed by the imaging lens 703 and outputs a microscope image.

[0043] The position adjustment camera 709 captures images of the wafer A, the tweezers 605, and the mesh holder 612 and outputs images for positioning.

[0044] The vertical Y stage 609 includes a motor for coarse adjustment and a piezoelectric actuator for fine adjustment, and changes the distance in the Y-axis direction between the wafer A and the observation lens barrel 701 (i.e., the relative position in the Y-axis direction of the first objective lens 708 with respect to the observation target) by translating the observation lens barrel 701 in the Y-axis direction.

[0045] The optical interference microscope system 610 acquires information about the position and three-dimensional shape of an object in real space through two-beam interference using white light. The optical path difference between the reflected light L1 from the object and the reflected light L2 from the reflecting mirror 705, which are combined at the second beam splitter 707, changes the interference state of the combined light obtained by combining the two reflected lights L1 and L2. The combined light constructively interacts (becomes brighter) when the phases of the reflected light L1 from the object and the reflected light L2 from the reflecting mirror 705 match, and destructively interacts (becomes darker) when the phases do not match, producing interference fringes of bright and dark images. Because the reference surface 705a of the reflecting mirror 705 is smoothly formed, the interference fringes reveal information about the three-dimensional shape of the object, such as the surface irregularities. The spacing between the interference fringes indicates a constant optical path difference depending on the wavelength of the illumination light L3 from the light source 711, so the distribution of the interference fringes (the number of interference fringes) corresponds to the elevation differences on the surface of the object.

[0046] In the optical interference microscope system 610, the relative position between the second objective lens 706 and the reflecting mirror 705 is fixed, whereas the relative position between the first objective lens 708 and the observation object is changed by driving the vertical Y stage 609. Driving the vertical Y stage 609 displaces the first objective lens 708 in the Y-axis direction, thereby adjusting the focus position of the observation object (i.e., the position where the intensity or contrast of the interference fringes observed in the microscope image is maximized). The focus position of the observation object in the Y-axis direction is associated with real space coordinate data of the first objective lens 708 (or the observation lens barrel 701).

[0047] FIG. 8 shows an enlarged perspective view of the tweezers 605. The tweezers 605 include a translational XYZ stage 801, a rotation mechanism 802, a rod 803, a tweezers drive mechanism 804 (second drive mechanism), and a tweezers tip 805. The translational XYZ stage 801 and the rotation mechanism 802 are mounted on the tweezers support unit 604. The tweezers drive mechanism 804 and the tweezers tip 805 are mounted on the rotation mechanism 802 via a rod 803. The rotation mechanism 802, the rod 803, the tweezers drive mechanism 804, and the tweezers tip 805 are tilted at an angle θ3 around the Z axis so that the tweezers tip 805 does not come into contact with the optical interference microscope system 610. In this embodiment, the angle θ3 is −20°. The translational XYZ stage 801 translates the tweezers tip 805 to any position. The rotation mechanism 802 rotates and moves the tweezers tip 805 around the longitudinal direction of the rod 803 as the rotation axis.

[0048] FIG. 9 shows an enlarged perspective view of the tweezers tip 805. FIG. 10 shows an arrow view of the tweezers tip 805. The tweezers tip 805 includes a tweezers driving mechanism 804, a first tweezers arm 901, and a second tweezers arm 902. The tweezers driving mechanism 804 drivably supports the first tweezers arm 901 and the second tweezers arm 902. The first tweezers arm 901 has a rectangular cross-sectional shape with a width b1 and a height c1 in the longitudinal direction of the rod 803 from the tweezers driving mechanism 804 to position C. The second tweezers arm 902 has a rectangular cross-sectional shape with a width b2 and a height c2 in the longitudinal direction of the rod 803 from the tweezers driving mechanism 804 to position C. Both the first tweezers arm 901 and the second tweezers arm 902 are beam members whose cross-sectional areas uniformly decrease from position C toward the tip E.

[0049] The first tweezers arm 901 and the second tweezers arm 902 have a tweezers arm upper surface 903 and a tweezers arm lower surface 905, which are planes perpendicular to the height c1 and height c2 directions. The first tweezers arm 901 and the second tweezers arm 902 further have a gripping surface 904 perpendicular to the tweezers arm upper surface 903 and the tweezers arm lower surface 905. The gripping surface 904 of the first tweezers arm 901 and the gripping surface 904 of the second tweezers arm 902 are formed to face each other parallel to each other at a position where the distance between them is smallest. The tweezers driving mechanism 804 moves the gripping surface 904 of the first tweezers arm 901 and the gripping surface 904 of the second tweezers arm 902 toward or away from each other while maintaining their parallelism. The width b2 of the second tweezers arm 902 is thicker than the width b1 so that the second tweezers arm 902 has higher rigidity in the direction of approaching or separating than the first tweezers arm 901.

[0050] In this embodiment, the cross-sectional area of ​​the tweezers arms at the tweezers tip 805 changes so as to decrease uniformly from position C to tip E in the longitudinal direction of the rod 803, but position C where the cross-sectional area decreases may be any position in the longitudinal direction of the rod 803, and position C where the cross-sectional area of ​​the first tweezers arm 901 and the second tweezers arm 902 decreases may be different positions in the longitudinal direction of the rod 803. Furthermore, the cross-sectional area of ​​the first tweezers arm 901 and the second tweezers arm 902 decreases uniformly in the longitudinal direction of the rod 803 from position C to tip E, but the cross-sectional area may increase or decrease midway from position C to tip E.

[0051] In this embodiment, the gripping surface 904 of the first tweezers arm 901 and the gripping surface 904 of the second tweezers arm 902 are flat surfaces facing each other, but may be stepped, tapered, or curved to match the shape of the sample piece B. In this embodiment, the tweezers arm upper surface 903 and the tweezers arm lower surface 905 of the first tweezers arm 901 and the second tweezers arm 902 are parallel flat surfaces, but may be stepped, tapered, or curved.

[0052] In this embodiment, the first tweezers arm 901 and the second tweezers arm 902 do not have sensors, but the gripping surface 904 may be provided with various sensors for voltage, temperature, contact, etc., or with a static electricity removal function. In this embodiment, the tweezers tip 805 operates to move the first tweezers arm 901 and the second tweezers arm 902 closer to or farther away from each other, but it may also move only the first tweezers arm 901 or only the second tweezers arm 902 closer to or farther away from each other.

[0053] Figure 11 shows a β-β cross section of Figure 10 when the sample piece is gripped. When removing sample piece B from wafer A, the longitudinal direction of the rod 803 of the tweezers tip 805 is tilted at an angle θ3 around the Z axis. The tweezers tip 805 is inserted into the sample piece groove 304 to a depth d1 of the sample piece lower part 501. Since the observation surface 302 of sample piece B is very thin in the Z axis direction, a gripping part 1101 is provided between the observation surface 302 and the support part 303 to prevent the bending moment of the plate from acting on the observation surface 302 when breaking off sample piece B. In this case, the distance between the observation surface 302 and the support part 303 satisfies the relationship d2 ≥ d1 / tan θ3 + d1 * tan θ3.

[0054] 12 shows a top view of the tweezers tip 805 and the sample piece processing groove 304 when viewed from the -Y axis direction. In the figure, the longitudinal direction of the rod 803 and the longitudinal direction of the sample piece B are perpendicular to the Z axis direction, and the breaking direction D5 is the -Z axis direction.

[0055] When the tweezers 605 are used to remove the sample piece B from the wafer A, the tweezers tip 805 is inserted into the sample piece processing groove 304 within a range e1. The sample piece processing groove 304 has a width f1+f2 on the side of the sample piece B in the direction of breakage D5 and a width f3 on the opposite side, based on the central plane of the sample piece B in the thickness direction. The widths f2 and f3 correspond to the width f2' of the first tweezers arm 901 and the width f3' of the second tweezers arm 902 in the insertion range e1, respectively, with the relationships f2'<f2 and f3'<f3. The width f1 corresponds to the amount of movement of the tweezers tip 805 during breakage.

[0056] Fig. 13 is a flowchart explaining the procedure for the mechanism 601 to pick up the sample piece B. Fig. 14 shows the state in which the tweezers tip 805 approaches the sample piece B. In the figure, the gripping surface 904 of the tweezers tip 805 is perpendicular to the Z-axis direction, the wafer surface 301 is perpendicular to the Y-axis direction, and the approach direction D4 is the Y-axis direction.

[0057] The method for preparing the sample piece B consists of four steps: approach S1, gripping S2, breaking S3, and lifting out S4. First, the step S1 of the approach operation of the tweezers tip 805 in the procedure for removing the sample piece B will be described. The sample piece B on the wafer A is rotated by the rotation stage 611 and translated by the coarse movement of the horizontal XZ stage 607 and the fine movement of the translation XYZ stage 801. First, the rotation by the rotation stage 611 aligns the gripping surface 904 of the tweezers tip 805 with the sample piece side surface 1403 in parallel. Next, the central plane of the gripping surface 904 of the first tweezers arm 901 and the gripping surface 904 of the second tweezers arm 902 is aligned with the central plane consisting of the side surface of the sample piece B. Then, the support portion 303 of the sample piece B and the end A 1401 of the tweezers tip 805 are aligned in the X-axis direction. Finally, the Y-axis coordinate of the end B1402 of the tweezers tip 805 is made to coincide with the Y-axis coordinate of the lower part 501 of the sample piece. The positioning method in this embodiment is merely an example, and the points where the coordinates are made to coincide are not limited to those described above.

[0058] 15 shows how the tweezers tip 805 grips the sample piece B. In FIGS. 15 to 18, the gripping surface 904 of the tweezers tip 805 and the side surface 1403 of the sample piece B are perpendicular to the Z-axis direction, the wafer surface 301 is perpendicular to the Y-axis direction, and the breaking direction D5 is the −Z-axis direction. In the gripping operation S2 step, the gripping surfaces 904 of the first tweezers arm 901 and the second tweezers arm 902 are brought into contact with the sample piece side surface 1403 by the tweezers driving mechanism 804 to grip the sample piece B.

[0059] 16 shows how sample piece B is broken off by translational movement of mechanism part 601. In step S3 of the sample piece B breaking-off operation using translational movement, the tweezers tip 805 holding sample piece B is translated in a breaking direction D5 by the translational XYZ stage 801. The tweezers tip 805 holding sample piece B is translated by the translational XYZ stage 801 until the support part 303 of sample piece B breaks. As a result, sample piece B is broken off from wafer A.

[0060] 17 shows how the sample piece B is broken off by the rotational movement of the mechanism part 601. In step S3, the sample piece B can also be broken off by rotational movement instead of translational movement. In step S3, which is the operation of breaking off the sample piece B using rotational movement, the tweezers tip 805 is rotated around the longitudinal axis of the rod 803 by the rotation mechanism 802. The sample piece B is pressed against the sample piece lower part 401 by the tweezers tip 805 with the support part 303 fixed, and is rotated in the rotational direction R1 around the longitudinal axis of the rod 803 passing through the support part 303. A bending moment in the rotational direction R1 acts on the support part 303 of the sample piece B, with the support part 303 as the fulcrum and the vicinity of the sample piece lower part 501 as the force point. The tip 805 of the tweezers gripping the sample piece B is rotated by the rotating mechanism 802 until the support portion 303 of the sample piece B breaks, and the sample piece B is broken off from the wafer A.

[0061] In the breaking operation step S3, if the sample piece B cannot be broken off with a single translational or rotational movement, the support portion 303 may be made easier to break by applying a translational or rotational vibration to the tip of the tweezers 805 holding the sample piece B.

[0062] FIG. 18 shows a two-dimensional cross-sectional view passing through the support portion 303 when the broken off sample piece shown in FIG. 17 is viewed from the −X axis direction.

[0063] 19 shows how the mechanism 601 lifts out the sample piece B. In the figure, the gripping surface 904 of the tweezers tip 805 and the side surface 1403 of the sample piece B are perpendicular to the Z-axis direction, the wafer surface 301 is perpendicular to the Y-axis direction, and the lift-out direction D6 is the Y-axis direction. Here, the lift-out operation S4 step of the tweezers tip 805 gripping the sample piece B in the procedure for removing the sample piece B will be described.

[0064] The tweezers tip 805 holding the sample piece B is translated in the lift-out direction D6 by the translational XYZ stage 801 until the Y-axis coordinate of the sample piece lower part 501 becomes higher than the wafer surface 301. In this embodiment, the lift-out direction D6 is the Y-axis direction, but it may be any direction that does not come into contact with the wafer A.

[0065] <Embodiment 1: Summary> The specimen preparation device 103 according to embodiment 1 reduces processing time by using tweezers 605 and a groove configuration that focuses on the method of breaking off specimen B to be used in a transmission electron microscope 104, thereby improving the throughput of the manufacturing process.

[0066] Second Embodiment In a second embodiment of the present invention, a modification of the first embodiment will be described.

[0067] In the first embodiment, the tweezers 605 are configured with two tweezers arms, the first tweezers arm 901 and the second tweezers arm 902. However, this is not limited to this, and the number and shape of the tweezers arms may be changed, and functions such as a sensor may be added.

[0068] In embodiment 1, when breaking off sample piece B from wafer A, the operation of translational XYZ stage 801 and rotation mechanism 802 is used, but this is not limited to this, and sample piece B may also be broken off using the operation of horizontal XZ stage 607 or tweezers drive mechanism 804.

[0069] <Regarding Modifications of the Present Invention> The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present disclosure, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0070] In the above embodiment, the location where the sample piece B is formed has been described as a groove, but the location where the sample piece is formed may have any shape. For example, the sample piece B may be formed in a hole-shaped location, or may be formed in any other excavation shape.

[0071] A...Wafer B...Specimen 101...Thin specimen observation system 102...Charged particle beam device 103...Specimen preparation device 104...Transmission electron microscope 201...Focused ion beam column 202...Specimen chamber 203...Secondary charged particle detector 204...Electron beam column 205...First drive mechanism 206...Stage 207...Second drive mechanism 208...Gas supply unit 209...Gas ion beam column 210...Electron beam 211...Focused ion beam 212...Gas ion beam 213...Wafer processing unit 301...Wafer surface 302...Observation surface 303...Support unit 304...Specimen processing groove 401...Specimen bottom 402...Slope of specimen processing groove 601...Mechanism of specimen preparation device 602...Gantry 603...Support 604...Tweezers support unit 605...Tweezers 606...Wafer suction chuck 607...Horizontal XZ stage 608...Surface plate 609...Vertical Y stage 610...Optical interference microscope system 611...Rotation stage 612...Mesh holder 801...Translational XYZ stage 802...Rotation mechanism 803...Rod 804...Tweezers drive mechanism 805...Tweezers tip 901...First tweezers arm 902...Second tweezers arm 903...Tweezers arm upper surface 904...Gripping surface 905...Tweezers arm lower surface 1101...Gripping portion 1401...End A 1402...End B 1403...Side surface of sample piece 1404...End of sample piece

Claims

1. A sample piece creating device for taking out a sample piece formed on a part of a sample from the sample, comprising: a pincer unit for gripping the sample piece by a first pincer arm and a second pincer arm; a first drive mechanism for moving the pincer unit; and a computer system for controlling the pincer unit and the first drive mechanism. The pincer unit has a second drive mechanism for driving at least one of the first pincer arm and the second pincer arm so as to adjust the distance between the first pincer arm and the second pincer arm. The second pincer arm is configured such that the rigidity in the direction driven by the second drive mechanism is higher than that of the first pincer arm. The computer system controls the second drive mechanism so as to narrow the distance between the first pincer arm and the second pincer arm to grip the sample piece, and then controls the first drive mechanism so as to exert an action of pressing the second pincer arm toward the first pincer arm to break off the gripped sample piece from the sample. Sample piece creating device.

2. The sample piece creating device according to claim 1, wherein the second pincer arm is configured to be wider than the first pincer arm in a plane parallel to the direction driven by the second drive mechanism and in the direction driven by the second drive mechanism, so that the rigidity is higher than that of the first pincer arm.

3. The sample piece creating device according to claim 1, wherein the first drive mechanism drives the pincer unit so as to break off the sample piece from the sample by translating the pincer unit in a direction from the second pincer arm toward the first pincer arm when the pincer unit is gripping the sample piece.

4. The sample piece creating device according to claim 1, wherein the first drive mechanism drives the pincer unit so as to break off the sample piece from the sample by rotating the pincer unit about the extending direction of the pincer unit as a rotation axis when the pincer unit is gripping the sample piece.

5. The first pincer arm and the second pincer arm each have a gripping surface for sandwiching the sample piece when the pincer unit grips the sample piece. The first drive mechanism rotates the pincer unit in a direction to press a portion of the gripping surface of the second pincer arm below the rotation axis against the gripping surface of the first pincer arm when the pincer unit is gripping the sample piece. The sample piece creating device according to claim 4.

6. The sample piece is formed in a thin sheet shape within a groove or hole of the sample. The first drive mechanism sandwiches the sample piece between the first pincer arm and the second pincer arm by introducing the tip of the pincer unit into the groove or hole when the space between the first pincer arm and the second pincer arm is not closed. The second drive mechanism grips the sample piece by narrowing the space between the first pincer arm and the second pincer arm when the sample piece is sandwiched between the first pincer arm and the second pincer arm. The sample piece creating device according to claim 1.

7. A part of the sample piece has a thin portion that is thinner than other parts of the sample piece. The first drive mechanism approaches the pincer unit to the sample piece at an angle such that when the pincer unit grips the sample piece, neither the first pincer arm nor the second pincer arm contacts the thin portion. The sample piece creating device according to claim 1.

8. A method for creating a sample piece by taking out a sample piece formed on a part of a sample from the sample, comprising: a step of gripping the sample piece using a pincer unit that grips the sample piece with a first pincer arm and a second pincer arm; a step of folding the gripped sample piece from the sample, wherein in the step of gripping the sample piece, at least one of the first pincer arm or the second pincer arm is driven to adjust the distance between the first pincer arm and the second pincer arm to grip the sample piece, the second pincer arm is configured to have a higher rigidity in the driving direction in the step of gripping the sample piece than the first pincer arm, and in the step of folding the sample piece from the sample, the pincer unit is controlled so that an action of pressing the second pincer arm toward the first pincer arm is exerted to fold the gripped sample piece from the sample. Method for creating a sample piece.

9. The method for creating a sample piece further comprises a step of forming a groove or a hole in the sample and forming the sample piece in a thin sheet shape. In the step of forming the groove, a first groove or a first hole formed on one surface side of the sample piece and a second groove or a second hole formed on the other surface side of the sample piece are formed, and an opening width of the first groove in a direction orthogonal to the one surface on the surface of the sample is smaller than an opening width of the second groove in a direction orthogonal to the other surface on the surface of the sample. The method for creating a sample piece according to claim 8.

10. In the step of gripping the sample piece, the pincer unit is moved so that the tip of the first pincer arm is introduced into the second groove and the tip of the second pincer arm is introduced into the first groove. In the step of gripping the sample piece, the first pincer arm contacts the sample piece from the one surface side and the second pincer arm contacts the sample piece from the other surface side to grip the sample piece. The method for creating a sample piece according to claim 9.

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