Test piece fabrication apparatus, test piece fabrication method, clamp unit

Abstract

The present invention aims to provide a sample preparation technique that increases the throughput of the sample manufacturing process by shortening the processing time for preparing sample preparations. The sample preparation apparatus of the present invention includes a clamping unit that holds the sample preparation by means of a first clamping arm and a second clamping arm; the second clamping arm is configured to have higher rigidity in the direction driven by the drive mechanism than the first clamping arm, thereby driving the clamping unit to press the second clamping arm toward the first clamping arm (see Figure 16).

Description

[Technical Field]

[0001] This invention relates to the technique of preparing test specimens. [Previous Technology]

[0002] In the semiconductor field in recent years, there has been a trend towards miniaturization or high integration of devices, such as three-dimensional circuits, resulting in complex circuits. During the manufacturing process, in order to detect defects in the circuit, a portion of the circuit is cut out as a test piece, and its cross-section is observed using a transmission electron microscope. The test piece is formed by applying a thin film treatment to the observation area where the transmission electron microscope encounters the electrons used for observation.

[0003] Patent Document 1 describes a method for preparing a sample sheet. In the same document, a laser beam processing or ion beam processing is applied to the surface of the object to be observed, thereby preparing a sample sheet having at least one support portion inside the groove. The sample sheet is then held with clamps and the support portion is broken, thus folding the sample sheet. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-003579 [Summary of the Invention]

[0005] [The problem the invention aims to solve]

[0006] In the semiconductor field, improving throughput by reducing the time for each inspection is of paramount importance. In the aforementioned prior art, laser beam processing or ion beam processing systems have long processing times, making it difficult to expect increased throughput. To improve throughput, the movement of the clamps must be accelerated. However, simply accelerating the movement leads to greater clamp deflection during folding, necessitating extensive machining of grooves on the sample to prevent the clamps from contacting areas outside the sample. Compared to the support portion, the amount of machining required for the grooves is greater, resulting in longer processing time and hindering throughput improvement. To reduce the amount of machining required for the grooves, increasing the rigidity of the clamps to suppress deflection increases the clamp thickness, thus requiring sufficient margin for the grooves.

[0007] This invention was created in view of the above-mentioned problems, and its object is to provide a sample preparation technique that increases the throughput of the sample manufacturing process by shortening the processing time for preparing the sample. [Means for Solving the Problems]

[0008] The sample preparation apparatus of the present invention includes a clamping unit that holds the sample sample by means of a first clamping arm and a second clamping arm; the second clamping arm is configured to have higher rigidity in the direction driven by the drive mechanism than the first clamping arm, thereby driving the clamping unit to press the second clamping arm toward the first clamping arm. [Effects of the Invention]

[0009] According to the sample preparation apparatus of the present invention, by shortening the processing time for preparing sample preparations, the throughput of the sample manufacturing process can be increased. Other issues, configurations, advantages, etc. of the present invention will become clear from the following description of embodiments.

Implementation Method

[0011] <Implementation Method 1>

[0012] FIG1 is a configuration diagram of a thin-film sample observation system with a sample preparation apparatus according to Embodiment 1 of the present invention. The thin-film sample observation system 100 is composed of a plurality of (n1) charged particle beam devices 102, a plurality of (n2) sample preparation apparatuses 103, and a plurality of (n3) transmission electron microscopes 104.

[0013] The thin-film sample observation system 100 uses a charged particle beam device 102 to perform laser beam processing or ion beam processing on wafer A, thereby forming a sample sheet B on the surface of wafer A. Then, wafer A containing sample sheet B is transferred to a sample sheet fabrication apparatus 103. The sample sheet fabrication apparatus 103 removes sample sheet B from wafer A. The sample sheet B removed from wafer A is transferred to a transmission electron microscope 104. The transmission electron microscope 104 measures sample sheet B.

[0014] Hereinafter, the X-axis, Y-axis, and Z-axis directions are mutually perpendicular in 3D space. The Y-axis direction is perpendicular to the device. The X-axis and Z-axis directions are two directions that are horizontal to the device.

[0015] FIG2 is a schematic diagram of the charged particle beam apparatus 102 according to the relevant embodiment. The charged particle beam apparatus 102 includes: a focusing ion beam tube 201, a sample chamber 202, a secondary charged particle detector 203, an electron beam tube 204, a first drive mechanism 205, a stage 206, a second drive mechanism 207, a gas supply unit 208, and a gas ion beam tube 209.

[0016] Inside the sample chamber 202, a stage 206 equipped with a first drive mechanism 205 and a second drive mechanism 207 is provided. The wafer A, the object of observation, is fixed on the stage 206. An electron beam microscope tube 204, a gas ion beam microscope tube 209, a secondary charged particle detector 203, and a gas supply unit 208 are tilted at a predetermined angle relative to the Y-axis direction from mutually opposite directions and are provided inside the sample chamber 202. A focused ion beam microscope tube 201 is provided inside the sample chamber 202 along the Y-axis direction. The electron beam microscope tube 204, the focused ion beam microscope tube 201, and the gas ion beam microscope tube 209 are arranged such that their optical axes intersect at predetermined positions on the upper surface of the wafer A, which is fixed to the upper part of the stage 206.

[0017] The configuration of the electron beam tube 204, the focused ion beam tube 201, and the gas ion beam tube 209 can also be interchanged. For example, either the electron beam tube 204 or the gas ion beam tube 209 can be set along the Y-axis, and the focused ion beam tube 201 can be set at a predetermined angle relative to the Y-axis.

[0018] The first drive mechanism 205 can rotate the stage 206 about the X-axis. The second drive mechanism 207 can translate the stage 206 in the X, Y, and Z axis directions, and rotate it about the Y-axis. By using the first drive mechanism 205 and the second drive mechanism 207, the surface of wafer A can be processed from a specified position and angle.

[0019] For objects within the defined irradiation area inside the sample chamber 202, the electron beam tube 204 can irradiate with the electron beam 210, the focused ion beam tube 201 can irradiate with the focused ion beam 211, and the gas ion beam tube 209 can irradiate with the gas ion beam 212. 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 etching gas and deposition gas to the irradiated object.

[0020] The charged particle beam apparatus 102 processes the surface of a wafer A formed using semiconductors such as silicon, and forms an observation surface of desired thickness on a sample sheet B suitable for transmission observation by a transmission electron microscope 104. A focused ion beam 211 scans and irradiates the wafer processing section 213, which is fixed relative to the stage 206, thereby performing imaging of the irradiated area and various processing (digging, trimming, etc.) caused by sputtering, as well as the formation of deposited films.

[0021] The stage 206 moves parallel to each other in the X, Y, and Z axes by the first drive mechanism 205 and the second drive mechanism 207, and rotates around the X and Y axes. In this way, the wafer A can be irradiated with the focused ion beam 211 from any angle to process the wafer A.

[0022] The charged particle beam device 102 scans and irradiates the wafer A with a focused ion beam 211 or an electron beam 210 to obtain an image of the surface. The image of the irradiated object is obtained by scanning ion microscopy, scanning electron microscopy, or absorption current method, etc. The image obtained by scanning ion microscopy or scanning electron microscopy is based on the image of secondary charged particles (secondary electrons or secondary ions) generated from the irradiated object by irradiation with a focused ion beam 211 or an electron beam 210. The image obtained by absorption current method is based on the image of 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).

[0023] The etching gas selectively promotes the etching of the irradiated object by the focused ion beam 211 according to the material of the irradiated object. The deposition gas forms a deposition film on the surface of the irradiated object by depositing a deposit of metal or insulator. The deposition film is formed by depositing solid components decomposed from the deposition gas supplied from the gas supply unit along with the irradiation of the charged particle beam onto the surface of the irradiated object.

[0024] Figure 3 is an enlarged perspective view of the wafer processing unit 213. The wafer surface 301 is perpendicular to the Y-axis, and the longitudinal direction of the sample wafer B is the X-axis. The wafer processing unit 213 is constructed using the sample wafer B, the wafer surface 301, the observation surface 302, the support portion 303, and the sample wafer processing groove 304. The wafer processing unit 213 forms the sample wafer processing groove 304 by irradiating the wafer surface 301 with a focused ion beam 211 to remove the periphery of the sample wafer B, thus processing the wafer A and the sample wafer B into a shape that is interconnected through at least one support portion 303. The observation surface 302 can be formed at any measurement location on the sample wafer B, and the observation surface 302 is measured using a transmission electron microscope.

[0025] Figure 4 is a top view of the wafer processing unit 213. Figure 5 is an α-α sectional view of the wafer processing unit 213 shown in Figure 4. The longitudinal direction of the sample wafer B in the figure 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 tilted at angles θ1 and θ2 respectively around the X-axis relative to the Z-axis direction.

[0026] The procedure for processing the wafer processing section 213 is described. First, in the wafer processing section 213, a focused ion beam 211 is irradiated from direction D2 by a charged particle beam device 102 to form a sample wafer processing trench 304. The sample wafer processing trench 304 has inclined surfaces 502 with angles θ1 and θ3 about the X-axis relative to the wafer surface 301 on directions D1 and D3.

[0027] Next, the wafer processing unit 213 uses the charged particle beam device 102 to irradiate the focused ion beam 211 from direction D1 or direction D3 to remove the lower part 501 of the sample wafer and the area around the support portion 303. In this way, a sample wafer B having the support portion 303 is formed.

[0028] Finally, the sample sheet B is irradiated with a focused ion beam 211 from 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 containing the sample sheet B processed in the above procedure is transferred to the sample sheet fabrication apparatus 103.

[0029] In this embodiment, the inclined surface 502 of the sample processing groove 304 has no angle change from the sample surface to the bottom. However, it can also be made into a stepped shape, a push-pull shape, or a curved shape. In this embodiment, the support portion 303 is a beam shape with a uniform cross-sectional area that does not change in the X-axis direction. However, it can also be made into a necked shape in the X-axis direction to facilitate breakage. In this processing procedure, the observation surface 302 is formed from the formation of the sample processing groove 304. However, the sample processing groove 304 can also be formed from the formation of the observation surface 302.

[0030] Figure 6 is a perspective view of the mechanism 601 included in the sample fabrication apparatus 103. The mechanism 601 (first drive mechanism) includes: a gantry 602, a support column 603, a clamp support 604, a clamp 605, a wafer adsorption chuck 606, a horizontal XZ stage 607, a flat plate 608, a vertical Y stage 609, an optical interference microscope system 610, a rotating stage 611, a grid support 612, and a wafer A. The horizontal XZ stage 607 and the rotating stage 611 are provided on the flat plate 608. The wafer adsorption chuck 606 is provided on the rotating stage 611. The grid support 612 for sample storage is provided on the horizontal XZ stage 607. The gantry 602 is provided on the flat plate 608 through the support column 603. On the gantry 602, clamps 605 are installed through clamp support 604, and optical interference microscope system 610 is installed through vertical Y stage 609.

[0031] The computer 620 is a computer that controls each part of the sample preparation apparatus 103. The computer 620 may be configured as part of the sample preparation apparatus 103 or as other devices (e.g., a control device disposed outside the sample preparation apparatus 103, or a computer configured as part of the thin film sample observation system 10, etc.).

[0032] After the wafer A containing the sample sheet B, which is transported out from the charged particle beam device 102, is fixed relative to the wafer adsorption chuck 606, the sample sheet B, the chuck 605, and the grid support 612 are aligned by the horizontal XZ stage 607, the vertical Y stage 609, and the clamp 605, and the sample sheet B is taken out and stored.

[0033] Figure 7 shows the configuration of the optical interference microscope system 610. The optical interference microscope system 610 includes: an observation tube 701, a light source tube 712, and a vertical Y-stage 609. The observation tube 701 and the light source tube 712 are integrally connected to each other in a perpendicular manner. The longitudinal direction of the light source tube 712 is the X-axis direction, and the longitudinal direction of the observation tube 701 is the Y-axis direction.

[0034] The light source lens 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 deflection filter.

[0035] The observation tube 701 is composed of 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 pair of object lenses 708 and a second pair of object lenses 706, and a position adjustment camera 709.

[0036] The first beam splitter 704 is located at a position where the central axes of the light source tube 712 and the observation tube 701 intersect. The first beam splitter 704 reflects the illumination light that travels from the light source 711 through the filter 710 toward the first end 701a on the observation object side of the two ends of the observation tube 701 (that is, toward the first pair of object lenses 708).

[0037] The first beam splitter 704 causes the combined light of the reflected light L2 from the second beam splitter 707 (described later) and the reflected light L1 from the object being observed to travel toward the second end 701b on the side of the observation camera 702 at both ends of the observation tube 701.

[0038] The second beam splitter 707 is disposed between the first beam splitter 704 and the first pair of objective lenses 708. The second beam splitter 707 splits the illumination light L3 from the first beam splitter 704 into a first direction along the central axis of the observation tube 701 and a second direction perpendicular to the central axis of the observation tube 701. The first direction is the Y-axis direction toward the first pair of objective lenses 708, as described later. The second direction is the X-axis direction toward the second pair of objective lenses 706, as described later.

[0039] The second beam splitter 707 causes the composite light obtained by superimposing the reflected light L1 from the object to be observed (described later) and the reflected light L2 from the mirror 705 to travel toward the second end 701b of the observation tube 701. The interference state of the composite light varies according to the optical path difference between the reflected light L1 from the object to be observed and the reflected light L2 from the mirror 705.

[0040] The first pair of objective lenses 708 is disposed at the first end 701a of the observation tube 701. The first pair of objective lenses 708 focuses the illumination light L3 traveling (penetrating) from the second beam splitter 707 in the first direction onto the object being observed (wafer A, clamp 605 and grid support 612).

[0041] The second pair of object lenses 706 is disposed in the second direction away from the second beam splitter 707. The second pair of object lenses 706 focuses the illumination light L3 traveling (reflected) from the second beam splitter 707 in the second direction onto the reflector 705.

[0042] The reflector 705 is disposed in a second direction away from the second pair of objective lenses 706. The reflector 705 is provided with a reference surface 705a, which is smoothly formed with a specified precision. The reflector 705 reflects the illumination light L3 from the second pair of objective lenses 706 to the second beam splitter 707 via the reference surface 705a.

[0043] An imaging lens 703 is disposed between the first beam splitter 704 and the observation camera 702. The imaging lens 703 forms an image of interference fringes by imaging the composite light from the first beam splitter 704.

[0044] An observation camera 702 is installed at the second end 701b of the observation tube 701. The observation camera 702 captures the interference fringes of the composite light formed by the imaging lens 703 and outputs a microscope image.

[0045] The positioning camera 709 outputs the positioning image obtained by capturing the wafer A, clamp 605 and grid support 612.

[0046] The vertical Y stage 609 includes a motor for coarse adjustment and a piezoelectric actuator for fine adjustment. The vertical Y stage 609 changes the distance in the Y-axis direction between the wafer A and the observation tube 701 (that is, the relative position of the first pair of objective lenses 708 to the object being observed) by translating the observation tube 701 in the Y-axis direction.

[0047] The optical interference microscope system 610 obtains information about the position and three-dimensional shape of the observed object in solid space based on the interference of two optical fluxes caused by white light. The optical path difference between the reflected light L1 from the observed object and the reflected light L2 from the mirror 705 synthesized in the second beam splitter 707 causes a change in the interference state of the synthesized light obtained by combining the two reflected lights L1 and L2. The synthesized light produces interference fringes of bright and dark images when the phases of the reflected light L1 from the observed object and the reflected light L2 from the mirror 705 are in sync, and when the phases are out of sync, they weaken each other (become brighter), and when the phases are out of sync, they become darker. Because the reference surface 705a of the mirror 705 is smoothly formed, the interference fringes represent information about the three-dimensional shape of the surface of the observed object, such as its unevenness. Because the spacing of the interference fringes is dependent on the wavelength of the illumination light L3 from the light source 711 and represents a constant optical path difference, the distribution of the interference fringes (the number of interference fringes) corresponds to the height difference of the surface of the observed object.

[0048] In the optical interference microscope system 610, the relative position between the second pair of objective lenses 706 and the reflecting mirror 705 is fixed, while the relative position between the first pair of objective lenses 708 and the object being observed changes according to the driving of the vertical Y-stage 609. By driving the vertical Y-stage 609, the first pair of objective lenses 708 is displaced in the Y-axis direction, thereby adjusting the focusing position of the object being observed (i.e., the position where the intensity or contrast of the interference fringes observed by the microscope image is greatest). The focusing position of the object in the Y-axis direction corresponds to the spatial coordinate data of the first pair of objective lenses 708 (or the observation tube 701).

[0049] Figure 8 is an enlarged perspective view of the clamp 605. The clamp 605 is constructed using a translation XYZ stage 801, a rotation mechanism 802, a rod 803, a clamp drive mechanism 804 (second drive mechanism), and a clamp end 805. The translation XYZ stage 801 and the rotation mechanism 802 are provided in the clamp support 604. The clamp drive mechanism 804 and the clamp end 805 are provided in the rotation mechanism 802 through the rod 803. The rotation mechanism 802, the rod 803, the clamp drive mechanism 804, and the clamp end 805 are tilted around the Z-axis by an angle θ3, so that the clamp end 805 does not contact the optical interference microscope system 610. In this embodiment, the angle θ3 is -20°. The translation XYZ stage 801 allows the clamp end 805 to be translated and moved to any position. The rotation mechanism 802 rotates the clamp end 805 about the longitudinal direction of the rod 803.

[0050] Figure 9 is an enlarged perspective view of the clamp end 805. Figure 10 is a view of the clamp end 805 in the direction of the arrow. The clamp end 805 includes: a clamp drive mechanism 804, a first clamp arm 901, and a second clamp arm 902. The clamp drive mechanism 804 supports and can drive the first clamp arm 901 and the second clamp arm 902. The first clamp arm 901, along the longitudinal direction of the rod 803, from the clamp drive mechanism 804 to position C, has a rectangular cross-sectional shape with a width b1 and a height c1. The second clamp arm 902, along the longitudinal direction of the rod 803, from the clamp drive mechanism 804 to position C, has a rectangular cross-sectional shape with a width b2 and a height c2. Both the first clamp arm 901 and the second clamp arm 902 are beam members whose cross-sectional area decreases uniformly from position C toward end E.

[0051] The first clamping arm 901 and the second clamping arm 902 have an upper surface 903 and a lower surface 905 of the clamping arm, which are planes perpendicular to the directions of height c1 and height c2. The first clamping arm 901 and the second clamping arm 902 further have a gripping surface 904 perpendicular to the upper surface 903 and the lower surface 905 of the clamping arm. The gripping surface 904 of the first clamping arm 901 and the gripping surface 904 of the second clamping arm 902 are formed parallel to each other at a position where the distance between them is minimal. The clamping drive mechanism 804 causes the gripping surfaces 904 of the first clamping arm 901 and the second clamping arm 902 to approach or move away while maintaining parallelism. The second clamping arm 902 is thicker than the first clamping arm 901 in width b2 so that its rigidity in the approaching or moving away direction is higher than that of the first clamping arm 901.

[0052] In this embodiment, the clamp arms are located in the clamp end 805, and the cross-sectional area of ​​the clamp arm decreases uniformly from position C toward end E along the longitudinal direction of the rod 803. However, the position C where the cross-sectional area decreases can be any position along the longitudinal direction of the rod 803, and the position C where the cross-sectional area of ​​the first clamp arm 901 and the second clamp arm 902 decreases can also be at different positions along the longitudinal direction of the rod 803. Moreover, the first clamp arm 901 and the second clamp arm 902 are shaped such that the cross-sectional area decreases uniformly from position C toward end E along the longitudinal direction of the rod 803, but the cross-sectional area can also increase or decrease along the route from position C to end E.

[0053] In this embodiment, the gripping surfaces 904 of the first clamping arm 901 and the second clamping arm 902 are mutually facing planes, but they can also be stepped, pushed, or bent, depending on the shape of the sample piece B. In this embodiment, the upper surface 903 and lower surface 905 of the clamping arms of the first clamping arm 901 and the second clamping arm 902 are parallel planes, but they can also be stepped, pushed, or bent.

[0054] In this embodiment, the first clamp arm 901 and the second clamp arm 902 do not have sensors, but the gripping surface 904 may have various sensors such as voltage, temperature, or contact sensors, or may have an electrostatic discharge function. In this embodiment, the clamping end 805 performs an action that moves the first clamp arm 901 and the second clamp arm 902 closer or further apart, but it may also move only the first clamp arm 901 or only the second clamp arm 902 closer or further apart.

[0055] Figure 11 is a β-β cross-sectional view of Figure 10 when the sample wafer is held. When the sample wafer B is removed from wafer A, the longitudinal direction of the clamp end 805 is tilted at an angle θ3 around the Z-axis by the tie rod 803. The clamp end 805 is inserted into the sample wafer processing groove 304 up to a depth d1 of the lower part 501 of the sample wafer. Because the observation surface 302 of the sample wafer B is very thin in the Z-axis direction, in order to prevent the bending moment of the plate from acting on the observation surface 302 when the sample wafer B is folded, the gripping part 1101 is provided between the observation surface 302 and the support part 303. At this time, the distance between the observation surface 302 and the support part 303 is d2 ≥ d1 / tanθ3 + d1 * tanθ3.

[0056] Figure 12 is a top view of the clamp end 805 and the sample plate processing groove 304 when viewed from the -Y axis direction. The longitudinal direction of the rod 803 and the longitudinal direction of the sample plate B in the figure are perpendicular to the Z axis direction, and the folding direction D5 is the -Z axis direction.

[0057] When the clamp 605 is used to remove the sample wafer B from wafer A, the clamp end 805 is inserted into the sample wafer processing groove 304 within range e1. The sample wafer processing groove 304 is based on the center plane of the sample wafer B in the thickness direction, and has a width f1+f2 on the side in the folding direction D5, and a width f3 on the opposite side. The widths f2 and f3 correspond to the widths f2' of the first clamp arm 901 and f3' of the second clamp arm 902 in the insertion range e1, respectively, and are in the relationship of f2'<f2 and f3'<f3. The width f1 corresponds to the amount of movement of the clamp end 805 during folding.

[0058] Figure 13 is a flowchart illustrating the procedure of the mechanism 601 removing the sample sheet B. Figure 14 shows the approach of the clamp end 805 to the sample sheet B. In the figure, the gripping surface 904 of the clamp end 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.

[0059] The method for making the sample sheet B consists of four steps: approach S1, gripping S2, folding S3, and lifting S4. First, the approach action S1 of the clamp end 805 in the sample sheet B removal procedure will be explained. The sample sheet B on wafer A is rotated by the rotary 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 rotational movement caused by the rotary stage 611 makes the gripping surface 904 of the clamp end 805 parallel to the single side 1403 of the sample sheet. Next, the center plane of the gripping surface 904 of the first clamp arm 901 and the gripping surface 904 of the second clamp arm 902, and the center plane formed by the side of the sample sheet B, are aligned. Next, the support portion 303 of the sample piece B and the end A1401 of the clamping end 805 are both aligned with the X-axis direction. Finally, the end B1402 of the clamping end 805 is aligned with the Y-axis coordinate of the lower part 501 of the sample piece. The positioning method in this embodiment is only one example, and the alignment of coordinates is not limited to the above.

[0060] Figure 15 shows the gripping pattern of sample sheet B held by the clamp end 805. In Figures 15-18, the gripping surface 904 of the clamp end 805 and the side surface 1403 of sample sheet B are perpendicular to the Z-axis direction, the wafer surface 301 is perpendicular to the Y-axis direction, and the folding direction D5 is the -Z-axis direction. In the gripping action S2 step, the gripping surface 904 of the first clamp arm 901 and the gripping surface 904 of the second clamp arm 902 are brought into contact with the side surface 1403 of the sample sheet via the clamp drive mechanism 804, and the sample sheet B is gripped.

[0061] Figure 16 illustrates the process of folding the sample wafer B via the translational movement of the mechanism 601. In step S3 of the sample wafer B folding operation using translational movement, the clamping end 805 holding the sample wafer B is translated in the folding direction D5 via the translational XYZ stage 801. The clamping end 805 holding the sample wafer B is translated via the translational XYZ stage 801 until the support portion 303 of the sample wafer B breaks. Thus, the sample wafer B is folded from wafer A.

[0062] Figure 17 shows the sample piece B being folded by the rotational movement of the mechanism 601. Step S3 replaces translational movement; the sample piece B can also be folded by rotational movement. In step S3, the folding action of sample piece B using rotational movement, the clamp end 805 rotates about the longitudinal axis of the rod 803 via the rotation mechanism 802. Sample piece B is pressed against the lower part 401 of the sample piece by the clamp end 805 with the support 303 fixed, and rotates about the longitudinal axis of the rod 803 passing through the support 303 in the rotational direction R1. A bending moment in the rotational direction R1 acts on the support 303 of sample piece B, with the support 303 as the fulcrum and the area near the lower part 501 of the sample piece as the point of force application. The clamp end 805 holding the sample piece B is rotated by the rotating mechanism 802 until the support part 303 of the sample piece B breaks, thus removing the sample piece B from the wafer A.

[0063] In the folding action S3 step, if the sample piece B cannot be folded by a single translation or rotation movement, a vibration of translation or rotation movement is applied to the end 805 of the clamp holding the sample piece B, thereby making the support part 303 easy to break.

[0064] Figure 18 is a 2D cross-sectional view of the sample sheet shown in Figure 17 when it is folded up and viewed from the -X axis direction through the support 303.

[0065] Figure 19 shows the state in which the mechanism 601 lifts the sample sheet B. In the figure, the gripping surface 904 of the clamp end 805 and the side surface 1403 of the sample sheet B are perpendicular to the Z-axis direction, the wafer surface 301 is perpendicular to the Y-axis direction, and the lifting direction D6 is the Y-axis direction. Here, the lifting action S4 step of the clamp end 805 holding the sample sheet B in the sample sheet removal procedure will be explained.

[0066] The clamp end 805 holding the sample sheet B is moved via the translation XYZ stage 801 in the lifting direction D6 until the Y-axis coordinate of the lower part 501 of the sample sheet is higher than the wafer surface 301. In this embodiment, the lifting direction D6 is the Y-axis direction, but any direction that does not contact the wafer A is acceptable.

[0067] <Embodiment 1: Summary> The sample preparation apparatus 103 of Embodiment 1 shortens the processing time by constructing the clamp 605 and groove with regard to the method of folding sample B for use in transmission electron microscope 104. In this way, the throughput of the manufacturing process can be increased.

[0068] <Embodiment 2> In Embodiment 2 of the present invention, a variation of Embodiment 1 will be described.

[0069] In Embodiment 1, the clamp 605 is composed of two clamp arms, the first clamp arm 901 and the second clamp arm 902, but it is not limited to this. The number or shape of the clamp arms may be changed, and functions such as sensors may be added.

[0070] In Embodiment 1, when folding the sample wafer B from wafer A, the operation of the translation XYZ stage 801 and the rotation mechanism 802 is used, but it is not limited to this. The operation of the horizontal XZ stage 607 or the clamp drive mechanism 804 can also be used to fold the sample wafer B.

[0071] <Modifications of the Invention> The present invention is not limited to the foregoing embodiments, but includes various modifications. For example, the above embodiments are described in detail for ease of understanding and explanation of this disclosure, and are not necessarily limited to having all the described configurations. Furthermore, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and another configuration can be added to the configuration of one embodiment. Moreover, regarding the configuration of each embodiment, other configurations can be added, deleted, or replaced.

[0072] In the above embodiments, it was described that the sample piece B is formed in a trench; however, the shape of the sample piece can be arbitrary. For example, the sample piece B can be formed in a hole-like area, or it can be formed in any other arbitrary excavation shape. [Simplified Explanation of the Diagram]

[0010] [Fig. 1] is a configuration diagram of the thin-film sample observation system equipped with a sample preparation apparatus according to Embodiment 1. [Fig. 2] is a schematic diagram of the charged particle beam device 102 according to the embodiment. [Fig. 3] is an enlarged perspective view of the wafer processing section 213. [Fig. 4] is a top view of the wafer processing section 213. [Fig. 5] is an α-α cross-sectional view of the wafer processing section 213 shown in Fig. 4. [Fig. 6] is a perspective view of the mechanism 601 provided in the sample preparation apparatus 103. [Fig. 7] is a configuration diagram of the optical interference microscope system 610. [Fig. 8] is an enlarged perspective view of the clamp 605. [Fig. 9] is an enlarged perspective view of the clamp end 805. [Fig. 10] is a view of the clamp end 805 in the direction of the arrow. [Fig. 11] is a β-β cross-sectional view of Fig. 10 when the sample is held. [Figure 12] is a top view of the clamping end 805 and the sample processing groove 304 as viewed from the -Y axis direction. [Figure 13] is a flowchart illustrating the procedure by which the mechanism 601 removes the sample B. [Figure 14] shows the clamping end 805 approaching the sample B. [Figure 15] shows the clamping end 805 holding the sample B. [Figure 16] shows the sample B being folded up by the translational movement of the mechanism 601. [Figure 17] shows the sample B being folded up by the rotational movement of the mechanism 601. [Figure 18] is a 2D cross-sectional view through the support 303 as the sample shown in Figure 17 is folded up, viewed from the -X axis direction. [Figure 19] shows the mechanism 601 lifting the sample B.

Claims

1. An apparatus for forming a sample sheet from a portion of a sample, comprising: a clamping unit for holding the sample sheet by means of a first clamping arm and a second clamping arm; a first drive mechanism for moving the clamping unit; and a computer system for controlling the clamping unit and the first drive mechanism; wherein... The aforementioned clamping unit includes: a second drive mechanism that drives at least one of the aforementioned first clamping arm or the aforementioned second clamping arm to adjust the gap between the aforementioned first clamping arm and the aforementioned second clamping arm; the aforementioned second clamping arm is configured to have higher rigidity in the direction driven by the aforementioned second drive mechanism than the aforementioned first clamping arm; the aforementioned computer system, after controlling the aforementioned second drive mechanism to narrow the gap between the aforementioned first clamping arm and the aforementioned second clamping arm to grip the aforementioned sample sheet, controls the aforementioned first drive mechanism to perform the function of pressing the aforementioned second clamping arm toward the aforementioned first clamping arm in order to fold the gripped sample sheet from the aforementioned sample.

2. As in the apparatus for fabricating the sample sheet in claim 1, wherein, The aforementioned second clamping arm is configured in a plane parallel to the direction driven by the aforementioned second driving mechanism and is wider than the aforementioned first clamping arm in the direction driven by the aforementioned second driving mechanism. As a result, the aforementioned rigidity is higher than that of the aforementioned first clamping arm.

3. As in the apparatus for fabricating the sample sheet in claim 1, wherein, When the aforementioned clamping unit holds the aforementioned sample sheet, the aforementioned first driving mechanism drives the aforementioned clamping unit so that the aforementioned clamping unit moves in a direction from the aforementioned second clamping arm to the aforementioned first clamping arm, thereby folding the aforementioned sample sheet from the aforementioned sample.

4. An apparatus for fabricating the sample sheet as described in claim 1, wherein, When the aforementioned clamping unit holds the aforementioned sample sheet, the aforementioned first driving mechanism drives the aforementioned clamping unit to rotate the aforementioned clamping unit with the extension direction of the aforementioned clamping unit as the rotation axis, thereby folding the aforementioned sample sheet from the aforementioned sample.

5. The apparatus for fabricating the sample sheet as described in claim 4, wherein, The aforementioned first clamp arm and the aforementioned second clamp arm each have a gripping surface for clamping the aforementioned sample sheet when the aforementioned clamp unit grips the aforementioned sample sheet; the aforementioned first drive mechanism rotates the aforementioned clamp unit in a direction that applies pressure to the aforementioned gripping surface of the aforementioned second clamp arm, which is lower than the aforementioned rotation axis, onto the aforementioned gripping surface of the aforementioned first clamp arm when the aforementioned clamp unit is gripping the aforementioned sample sheet.

6. An apparatus for fabricating a sample sheet as described in claim 1, wherein, The aforementioned sample sheet is formed into a thin sheet within the groove or hole of the aforementioned sample; the aforementioned first driving mechanism, before the aforementioned first clamping arm and the aforementioned second clamping arm are tightly closed, guides the end of the aforementioned clamping unit into the aforementioned groove or hole, thereby clamping the aforementioned sample sheet between the aforementioned first clamping arm and the aforementioned second clamping arm; the aforementioned second driving mechanism, while clamping the aforementioned sample sheet between the aforementioned first clamping arm and the aforementioned second clamping arm, grips the aforementioned sample sheet by narrowing the gap between the aforementioned first clamping arm and the aforementioned second clamping arm.

7. An apparatus for fabricating a sample sheet as described in claim 1, wherein, A portion of the aforementioned sample sheet has a thinner portion than the other portions of the aforementioned sample sheet; the aforementioned first drive mechanism brings the aforementioned clamping unit close to the aforementioned sample sheet at an angle where neither the aforementioned first clamping arm nor the aforementioned second clamping arm contacts the aforementioned thinner portion when the aforementioned clamping unit holds the aforementioned sample sheet.

8. A method for manufacturing a sample sheet formed from a portion of a sample and removing it from the sample, comprising: a step of holding the sample sheet using a clamping unit that holds the sample sheet by means of a first clamping arm and a second clamping arm; and a step of folding the held sample sheet from the sample; wherein, In the step of holding the aforementioned sample sheet, at least one of the aforementioned first clamping arm or the aforementioned second clamping arm is driven to adjust the gap between the aforementioned first clamping arm and the aforementioned second clamping arm, thereby holding the aforementioned sample sheet; the aforementioned second clamping arm is configured to have higher rigidity in the direction of drive during the step of holding the aforementioned sample sheet than the aforementioned first clamping arm; in the step of folding the aforementioned sample sheet from the aforementioned sample, in order to fold the aforementioned held sample sheet from the aforementioned sample, the aforementioned clamping unit is controlled to perform the function of pressing the aforementioned second clamping arm toward the aforementioned first clamping arm.

9. The method for preparing the sample as described in request item 8, wherein, The aforementioned method for making a sample sheet further includes the steps of: forming a groove or hole in the aforementioned sample and forming a sheet-like sample sheet; in the step of forming the aforementioned groove, a first groove or first hole is formed on one side of the aforementioned sample sheet, and a second groove or second hole is formed on the other side of the aforementioned sample sheet; the opening width of the aforementioned first groove in a direction orthogonal to one side of the aforementioned sample sheet is smaller than the opening width of the aforementioned second groove in a direction orthogonal to the other side of the aforementioned sample sheet.

10. The method for preparing the sample as described in claim 9, wherein, In the step of holding the aforementioned sample sheet, the aforementioned clamping unit is moved such that the end of the aforementioned first clamping arm is inserted into the aforementioned second groove, and the end of the aforementioned second clamping arm is inserted into the aforementioned first groove; in the step of holding the aforementioned sample sheet, the aforementioned first clamping arm contacts the aforementioned sample sheet from one of the aforementioned face sides, and the aforementioned second clamping arm contacts the aforementioned sample sheet from the aforementioned other face side, thereby holding the aforementioned sample sheet.

11. A clamping unit for removing a sample sheet formed from a portion of a sample from the sample, comprising: a first clamping arm and a second clamping arm for holding the sample sheet; a drive mechanism for driving at least one of the first clamping arm or the second clamping arm to adjust the gap between the first clamping arm and the second clamping arm; the second clamping arm being configured to have a higher rigidity in the direction driven by the drive mechanism than the first clamping arm; after holding the sample sheet by narrowing the gap between the first clamping arm and the second clamping arm, moving the clamped sample sheet to press the second clamping arm toward the first clamping arm in order to remove the sample sheet from the sample.

Images