Jig, and sample processing method

Abstract

To provide a jig that can easily adjust a charged particle beam irradiation position relative to a sample, and a sample processing method using the jig.SOLUTION: A jig has a support part, a sample fixing part, and a stopper. The support part has a wall portion extending in a first direction and a second direction orthogonal to the first direction. The sample fixing part has a sample holding surface on which a sample can be mounted and a sample holding mechanism, and is rotatable. The stopper is provided on a top face of the wall portion, and is brought into contact with the sample fixing part when the sample fixing part rotates.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present embodiment relates to a jig and a sample processing method. [Background technology]

[0002] In order to prepare samples for observation under electron microscopes, etc., charged particle beam devices may be used to microfabricate samples with ion beams. When different structures exist within a sample, for example, when the direction of incidence of the ion beam overlaps with the boundary between structures within the sample, curtaining may occur, as one structure is processed at a higher rate than the other structures. Similarly, when a sample has a periodic structure, curtaining may occur when the direction of incidence of the ion beam overlaps with the structural pattern within the sample. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2021 / 0350998 [Patent Document 2] US Patent Application Publication No. 2012 / 0119109 [Non-patent literature]

[0004] [Non-Patent Document 1] SEM sample stage, EM Japan Co., Ltd., [online], [searched May 23, 2023], Internet<https: / / www.em-japan.com / stub.html> Summary of the Invention [Problem to be solved by the invention]

[0005] A jig and a sample processing method are provided that can easily adjust the irradiation position of a charged particle beam on a sample. [Means for solving the problem]

[0006] The jig of the embodiment has a support portion, a sample fixing portion, and a stopper. The support portion has a wall portion extending in a first direction and a second direction perpendicular to the first direction. The sample fixing portion has a sample holding surface on which a sample can be mounted and a sample holding mechanism, and is rotatable. The stopper is provided on an upper surface of the wall portion and comes into contact with the sample fixing portion when the sample fixing portion rotates. [Brief description of the drawings]

[0007] [Figure 1] 1 is a schematic diagram showing an example of the configuration of a charged particle beam device in a first embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of the configuration of a jig 130 according to the first embodiment. [Diagram 3] FIG. 2 is a diagram showing an example of the configuration of a jig 130 according to the first embodiment. [Figure 4] FIG. 2 is a top view showing an example of the configuration of a jig 130 in the first embodiment. [Diagram 5] FIG. 2 is a diagram showing an example of the configuration of a charged particle beam apparatus in a case where a sample 140 is placed in the first embodiment. [Figure 6A] 5A to 5C are diagrams showing an example of an angle adjustment operation of a sample 140 using a jig 130 in the first embodiment. [Figure 6B] 5A to 5C are diagrams showing an example of an angle adjustment operation of a sample 140 using a jig 130 in the first embodiment. [Figure 6C] 5A to 5C are diagrams showing an example of an angle adjustment operation of a sample 140 using a jig 130 in the first embodiment. [Figure 7A] 5A to 5C are diagrams showing an example of an angle adjustment operation of a sample 140 using a jig 130 in the first embodiment. [Figure 7B] 5A to 5C are diagrams showing an example of an angle adjustment operation of a sample 140 using a jig 130 in the first embodiment. [Figure 7C] 5A to 5C are diagrams showing an example of an angle adjustment operation of a sample 140 using a jig 130 in the first embodiment. [Figure 8A] 5A to 5C are diagrams showing an example of an angle adjustment operation of a sample 140 using a jig 130 in the first embodiment. [Figure 8B] 5A to 5C are diagrams showing an example of an angle adjustment operation of a sample 140 using a jig 130 in the first embodiment. [Figure 8C] 5A to 5C are diagrams showing an example of an angle adjustment operation of a sample 140 using a jig 130 in the first embodiment. [Figure 9] FIG. 2 is a flow chart showing an example of a sample processing method according to the first embodiment. [Figure 10] FIG. 11 is a diagram showing an example of the configuration of a jig 130 in a modified example of the first embodiment. [Figure 11] FIG. 11 is a top view showing a configuration example of a jig 130 in a modified example of the first embodiment. [Figure 12] FIG. 11 is a top view showing a configuration example of a jig 130 according to a second embodiment. [Figure 13] FIG. 11 is a top view showing an example of the configuration of a jig 130 according to a third embodiment. [Figure 14] FIG. 13 is an enlarged view of an example of a cross-sectional view of a sample 140 in a fourth embodiment. [Figure 15A] FIG. 13 is an enlarged view of an example of a cross-sectional view of a sample 140 when irradiated with an ion beam 111 in a fourth embodiment. [Figure 15B] FIG. 13 is an enlarged view of an example of a cross-sectional view of a sample 140 after irradiation with an ion beam 111 in a fourth embodiment. [Figure 15C] FIG. 13 is an enlarged view of an example of a top view of a sample 140 after irradiation with an ion beam 111 in a fourth embodiment. [Figure 16] FIG. 13 is a top view showing an example of a hole 146 having a diameter D1 in the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present invention is not limited to this embodiment. The drawings are schematic or conceptual, and the ratio of each part is not necessarily the same as the actual one. In the specification and drawings, elements similar to those described above with respect to the previous drawings are given the same reference numerals, and detailed descriptions are omitted as appropriate.

[0009] (First embodiment) FIG. 1 is a schematic diagram showing a configuration example of a charged particle beam device in a first embodiment. The charged particle beam device in the first embodiment processes a sample held by a jig, for example, by using an ion beam. The charged particle beam device may be, for example, a focused ion beam (FIB) device. Also, it may be an FIB-SEM device equipped with an FIB device and a scanning electron microscope (SEM). The following description will be given taking the FIB-SEM device as an example.

[0010] The FIB-SEM device 100 has an FIB column 110 and an SEM column 120, and can be equipped with a jig 130 capable of holding a sample.

[0011] The FIB column 110 generates and focuses ions to irradiate an ion beam 111. By irradiating a sample 140 placed on a jig 130 with the ion beam 111 from the FIB column 110, any desired location of the sample 140 can be processed.

[0012] The SEM column 120 irradiates an electron beam and detects secondary electrons emitted from the sample 140 by the irradiation of the electron beam. After the sample 140 is irradiated with an ion beam 111 from the FIB column 110, the SEM column 120 irradiates an electron beam and detects secondary electrons at any point on the sample 140 irradiated with the ion beam 111. This makes it possible to observe any point on the sample 140.

[0013] The jig 130 can hold the sample 140. The sample 140 is placed on and fixed to the jig 130. The portion of the jig 130 on which the sample 140 is placed is inclined. In other words, the jig 130 has an inclined surface on which the sample 140 can be placed. The jig 130 can be inclined in the Z direction about the Y axis. For example, when it is desired to adjust the angle of the sample 140 fixed to the jig 130 with respect to the ion beam 111 irradiated from the FIB column 110, the jig 130 may be inclined in the Z direction about the Y axis.

[0014] 2 and 3 are diagrams showing a configuration example of the jig 130 in the first embodiment. Also, Fig. 4 is a top view showing the configuration example of the jig 130 in the first embodiment. All elements of the jig 130 in Figs. 2, 3, and 4 are in their initial positions.

[0015] The jig 130 is capable of holding the sample 140. For the jig 130, it is preferable to use a material that is unlikely to generate dust, sublime, or melt due to, for example, an ion beam or an electron beam. In addition, it is preferable to use a conductive material so that charging by electrons or ions can be suppressed when the jig 130 is irradiated with an electron beam or an ion beam.

[0016] In order to improve the controllability of the jig 130, it is preferable that the jig 130 is made of, for example, a relatively light metal. For example, aluminum may be used for the jig 130. In the jig 130, the respective elements described below may be made of the same material or different materials. For example, all the elements of the jig 130 may be made of aluminum, or some of the elements of the jig 130 may be made of aluminum and the other elements may be made of a material other than aluminum.

[0017] The jig 130 includes a support portion 131 , a sample fixing portion 132 , and a stopper 133 .

[0018] The support portion 131 includes a floor portion 131a, a wall portion 131b, a support shaft 131c, and a pair of fixing portions 131d. Although an example in which a pair of fixing portions 131d is provided is shown in Fig. 2, Fig. 3, and Fig. 4, the present invention is not limited to this example, and for example, only one fixing portion 131d may be provided. The following description will be focused mainly on the configuration of one fixing portion 131d.

[0019] The floor portion 131a extends in the X direction and the Y direction. The floor portion 131a may be, for example, circular when viewed from the Z direction.

[0020] The wall portion 131b extends in the Y direction and the Z direction from the floor portion 131a. When the floor portion 131a is circular, the wall portion 131b may be provided on the diameter of the floor portion 131a. In this case, the length of the wall portion 131b in the Y direction may be the same as the diameter of the floor portion 131a. The wall portion 131b has a hole for rotatably holding a rotation shaft 132d of the sample fixing portion 132 described later, and a hole for screwing with the fixing portion 131d described later. The height of the wall portion 131b in the Z direction may be, for example, the same as or higher than the height of the sample fixing portion 132 described later in the Z direction. More specifically, the height of the wall portion 131b in the Z direction may be, for example, the same as or higher than the height of a roof portion 132f of the sample fixing portion 132 described later when the rotation shaft 132d of the sample fixing portion 132 is held at the initial position.

[0021] The support shaft 131c extends in the Z direction from the floor portion 131a. More specifically, the support shaft 131c extends in the Z direction from a surface of the floor portion 131a that is opposite to a surface that is in contact with the wall portion 131b. That is, the support shaft 131c and the wall portion 131b extend in opposite directions to each other in the Z direction. In addition, if the floor portion 131a is circular, the support shaft 131c may extend in the Z direction from, for example, a center portion of the circle of the floor portion 131a.

[0022] The fixing portion 131d is provided on a side surface of the wall portion 131b. Specifically, the fixing portion 131d may be provided on a side surface of the wall portion 131b to which the Y direction is a normal direction. That is, the fixing portion 131d may be provided on a side surface of the wall portion 131b on which the sample fixing portion 132 and the stopper 133 described later are not provided.

[0023] The fixing part 131d is screwed into a hole formed so as to extend from the side surface of the wall part 131b in the Y direction. When the fixing part 131d is moved to the inside of the wall part 131b, one end of the fixing part 131d comes into contact with a rotating shaft 132d (described later) inside the wall part 131b. As a result, the rotating shaft 132d is fixed inside the wall part 131b, and the sample fixing part 132 is also fixed at a predetermined position. In addition, when the fixing part 131d is screwed into the wall part 131b, the other end of the fixing part 131d is exposed from the wall part 131b. The other end of the fixing part 131d may protrude from the side surface of the wall part 131b in the Y direction, or may be located inside the side surface of the wall part 131b.

[0024] The fixing portion 131d and a hole formed in the side surface of the wall portion 131b may be, for example, screwable.

[0025] A plurality of fixing parts 131d may be provided, for example, on the side surface of the wall part 131b on which the sample fixing part 132 and the stopper 133 described later are not provided, that is, on two side surfaces having the Y direction as a normal direction. In this case, inside the wall part 131b, the rotation shaft 132d is in contact with a pair of fixing parts 131d at two points, respectively, and fixed thereto.

[0026] Hereinafter, a case where the fixing portion 131d can be screwed into a hole formed in the side surface of the wall portion 131b will be described as an example. Note that, in addition to the above-mentioned screw, the fixing portion 131d may be made of, for example, rubber, and may be fitted into a hole formed so as to extend in the Y direction from the side surface of the wall portion 131b to fix the rotating shaft 132d.

[0027] The sample fixing part 132 includes a sample support surface 132a, a sample support part 132b, a step 132c, a rotation axis 132d, an arcuate part 132e, a roof part 132f, and a shoulder part 132g. The sample support surface 132a, the sample support part 132b, the step 132c, the arcuate part 132e, the roof part 132f, and the shoulder part 132g, i.e., the part of the sample fixing part 132 other than the rotation axis 132d, function as a sample placement part 132h. The sample placement part 132h of the sample fixing part 132 may be, for example, semi-cylindrical.

[0028] The sample support surface 132a is a surface of the sample fixing portion 132 that is located opposite to the surface that contacts the wall portion 131b. In other words, the sample support surface 132a is a surface of the sample placement portion 132h that is located opposite to the surface that contacts the wall portion 131b. The sample 140 is placed on the sample support surface 132a. It is preferable that the sample 140 is placed so that the surface having the observation target portion is located opposite to the surface that contacts the sample support surface 132a. Here, the observation target portion can be said to be a portion of the sample 140 that is processed by the ion beam 111 irradiated from the FIB column 110. When viewed from the Y direction, the sample support surface 132a is inclined so that the angle θ132 that it forms with the arc portion 132e is an acute angle. For example, the angle θ132 may be the same as the irradiation angle of the ion beam 111 irradiated from the FIB column 110.

[0029] The sample support surface 132a is provided with a sample support portion 132b and a step 132c.

[0030] The sample holder 132b includes, for example, a screw and a leaf spring. The sample holder 132b functions as a part of the sample holding mechanism. With the sample 140 placed on the sample holder surface 132a, the sample 140 is fixed to the sample holder surface 132a by clamping the sample 140 at a location other than the observation target portion with the leaf spring.

[0031] When viewed from the Y direction, the step 132c protrudes from the sample support surface 132a in at least one of the X and Z directions, or in both the X and Z directions. When the sample 140 has a substantially rectangular shape, the step 132c supports the position of at least one side of the sample 140. The step 132c may be composed of a linear member or may be composed of two or more point-shaped members, as long as the step 132c has a shape capable of supporting at least one side of the sample 140.

[0032] The step 132c functions as another part of the sample holding mechanism. That is, the sample holding portion 132b and the step 132c cooperate to function as the sample holding mechanism. The sample holding portion 132b alone can function as the sample holding mechanism, and the step 132c alone can function as the sample holding mechanism. The step 132c may be formed integrally with the sample holding surface 132a, or may be attached separately from the sample holding surface 132a. For example, the step 132c may be in a form that protrudes from the sample holding surface 132a, or may be in a form in which the step 132c is attached as a convex member to the substantially flat sample holding surface 132a.

[0033] When the sample 140 is placed on the sample support surface 132a, if at least a part of one surface of the sample 140 comes into contact with the step 132c, the step 132c is preferably capable of holding the sample 140 such that one side of the sample 140 is substantially parallel to the floor portion 131a with the rotation axis 132d held at the initial position. In other words, the step 132c is preferably configured to be capable of holding the sample 140 such that one side of the sample 140 is substantially parallel to the floor portion 131a in the Y direction with the rotation axis 132d held at the initial position. This allows the angle of the sample with respect to the Y axis to be aligned, for example, when the sample 140 is replaced and a new sample is placed on the sample support surface 132b.

[0034] The rotation shaft 132d extends in the X direction from the sample placement portion 132h in the sample fixing portion 132. The rotation shaft 132d penetrates the wall portion 131b and is rotatably held by a hole in the wall portion 131b. The rotation shaft 132d may be, for example, a screw that makes the sample fixing portion 132 rotatable. The sample fixing portion 132 can be rotated relative to the wall portion 131b about the rotation shaft 132d by operating the rotation shaft 132d. The sample fixing portion 132 may be rotated clockwise or counterclockwise about the rotation shaft 132d relative to the wall portion 131b.

[0035] In the sample fixing part 132, the sample placement part 132h is, for example, columnar and has an arc part 132e. In this case, the arc part 132e has an arc shape when viewed from the X direction and corresponds to the outer periphery of the columnar shape. The radius of the arc part 132e is, for example, shorter than the length of the wall part 131b in the Y direction and the length in the Z direction. By configuring the sample fixing part 132 to have the arc part 132e, it is possible to prevent interference with the floor part 131a when the sample fixing part 132 rotates. This allows the distance between the sample fixing part 132 and the floor part 131a to be shortened, so that the entire jig 130 can be configured in a space-saving manner. In addition, by appropriately setting the radius of the arc part 132e, the sample fixing part 132 is held by the floor part 131a via the arc part 132e, so that it is possible to reduce the load due to gravity when the rotation axis 132d is held by the hole in the wall part 131b.

[0036] The sample fixing part 132 may be provided with a roof part 132f that is inclined like a roof from the center of the arc part 132e or its vicinity when viewed from the X direction. In other words, the roof part 132f may not be parallel to the upper surface of the wall part 131b of the support part 131. The roof part 132f is inclined so that the center of the circle is closest to the upper surface of the wall part 131b and gradually moves away from the upper surface of the wall part 131b. In other words, the roof part 132f is the upper surface of the sample fixing part 132 that is inclined from the center of the circle toward the floor part 131a. As shown by 132f1 and 132f2 in FIG. 2, a plurality of roof parts 132f may be provided. The sample fixing part 132 may be provided with a plurality of roof parts 132f and shoulder parts 132g described later by cutting the end of the semicircular shape having the arc part 132e when viewed from the X direction. Furthermore, the extension lines of the roof portions 132f may or may not overlap with the centers of the arc portions 132e.

[0037] The roof portion 132f2 has, for example, a roof portion 132f2-α and a roof portion 132f2-β. When the sample fixing portion 132 is viewed from the X direction, the rotation angle from the state where the sample placement portion 132h and the rotation shaft 132d are held in the initial position until the stopper 133 described later and the roof portion 132f2 come into contact with each other is approximately equal to the inclination angles θ2α and θ2β of the roof portion 132f2. In other words, when the sample fixing portion 132 is viewed from the X direction, the rotation angle of the sample fixing portion 132 from the state where the sample placement portion 132h and the rotation shaft 132d are held in the initial position until the stopper 133 described later and the roof portion 132f2 come into contact with each other is the inclination angle θ2α or θ2β.

[0038] Like the roof portion 132f2, the roof portion 132f1 also has, for example, a roof portion 132f1-α and a roof portion 132f1-β. When the sample fixing portion 132 is viewed from the X direction, the sample fixing portion 132 can rotate from a state in which the sample fixing placement portion 132h and the rotation shaft 132d are held in their initial positions until the stopper 133 described later comes into contact with the roof portion 132f1, and the angle is an inclination angle θ1α or θ1β (not shown).

[0039] The inclination angle θ2α of the roof portion 132f2-α and the inclination angle θ2β of the roof portion 132f2-β may be the same or different. The inclination angle θ1α of the roof portion 132f1-α and the inclination angle θ1β of the roof portion 132f1-β may be the same or different. When the inclination angles are different, more inclination angles can be set than when the inclination angles θ1α and θ1β, and θ2α and θ2β are the same. This increases the number of types of samples that can be placed on the same jig 130 when there are multiple samples with different optimal inclination angles for curtaining countermeasures.

[0040] In the sample fixing part 132, the center of the arc part 132e does not necessarily have to coincide with the rotation axis 132d of the sample fixing part 132. In this case, the tilt angles θ1α, θ1β, θ2α, and θ2β in the figure do not strictly coincide with the rotation angle of the sample fixing part 132. Even in this case, the sample 140 fixed to the sample fixing part 132 can be rotated so that the angle from the initial position with respect to the irradiation direction of the ion beam 111 changes according to the tilt angles θ1α, θ1β, θ2α, and θ2β.

[0041] In the sample fixing portion 132, shoulders 132g1 and 132g2 are provided between the roof portion 132f1 and the arc portion 132e, and between the roof portion 132f1 and the roof portion 132f2. The shoulders 132g2 are a part of the roof portion 132f2, and are the ends opposite the centers of the roof portions 132f2-α and 132f2-β, when the centers of the circles are taken as one end. The shoulders 132g1 are a part of the roof portion 132f1, and are the ends that are the boundaries between the roof portion 132f1-α and the arc portion 132e, and between the roof portion 132f1-β and the arc portion 132e. Similar to the roof portion 132f, multiple shoulders 132g may be provided. In this case, when the stopper 133 described later comes into contact with the roof portion 132f, for example, if at least the shoulder portion 132g comes into contact with the lower surface of the stopper 133, the rotation of the sample fixing portion 132 stops.

[0042] The stopper 133 is provided on the upper surface of the wall portion 131b in the Z direction. The stopper 133 has a base portion 133a and a tip portion (convex portion) 133b. The base portion 133a of the stopper 133 is provided on the upper surface of the wall portion 131b so as to be rotatable in the XY plane. The tip portion 133b of the stopper 133 can protrude from the wall portion 131b in the XY plane when viewed from the Z direction. In other words, the stopper 133 can move from an initial position where it does not protrude from the wall portion 131b in the X direction when viewed from the Z direction to a protruding position where at least a part of it protrudes from the wall portion 131b in the X direction when viewed from the Z direction. When the sample fixing portion 132 is rotated in a state where the stopper 133 protrudes from the wall portion 131b, the roof portion 132f comes into contact with the lower surface of the stopper 133. The stopper 133 has a function of limiting the range of rotation of the sample fixing part 132 about the rotation axis 132d.

[0043] Two stoppers 133 may be provided to correspond to the clockwise and counterclockwise rotations of the sample fixing part 132. In the first embodiment, the axis of the stopper 133 is provided near the center of the upper surface of the wall part 131b in the Z direction to enable rotation, but the shape of the stopper 133 is not limited thereto.

[0044] When the sample fixing part 132 is rotated around the rotation axis 132d, the stopper 133 comes into contact with the sample fixing part 132 at a predetermined position. That is, when the sample fixing part 132 is rotated around the rotation axis 132d, the roof part 132f of the sample fixing part 132 comes into contact with the lower surface of the stopper 133. By stopping the rotation of the sample fixing part 132 when the lower surface of the stopper 133 comes into contact with the roof part 132f, the angle of the surface having the observation target part of the sample 140 with respect to the irradiation direction of the ion beam 111 can be adjusted.

[0045] The tip 133b of the stopper 133 may be formed as a convex portion, for example. Hereinafter, the tip 133b of the stopper 133 is also referred to as the convex portion 133b. The stopper 133 may have the convex portions 133b formed thereon, for example, in accordance with the number of the roof portions 132f. The convex portion 133b is an example of the shape of the end portion of the stopper 133 opposite to the base portion 133a fixed to the upper surface of the wall portion 131b in the Z direction, that is, the tip portion 133b side. The stopper 133 having the convex portion does not have a straight line from the base portion 133a to the tip portion 133b on the XY plane. In other words, the stopper 133 has a shape in which the width increases midway from the base portion 133a to the tip portion 133b of the stopper 133.

[0046] The width of the base 133a of the stopper 133 and the width of the tip (convex) 133b may be substantially the same. When the width of the base 133a and the width of the tip (convex) 133b of the stopper 133 are substantially the same, the width of the stopper 133 from the base 133a to the tip (convex) 133b becomes narrower, and at the tip (convex) 133b, it expands to substantially the same width as the base 133a. With this shape, when the convex portion of the stopper 133 is protruded from the wall portion 131b in the X direction, the stopper 133 can come into contact with the roof portion 132f1 while avoiding contact with the roof portion 132f2.

[0047] For example, when the number of roof portions 132f is n, where n is a natural number, the stopper 133 has n-1 convex portions. When the stopper 133 has two or more convex portions as shown in FIG. 11, the two or more convex portions may all be wider than the base 133a in the XY plane, or the width of the base 133a and the width of the convex portions may be approximately the same. When the stopper 133 has two or more convex portions and the width of the base 133a and the width of the convex portions are approximately the same, the convex portions closer to the base 133a in the XY plane may have a shape in which the width becomes wider and then gradually narrower. By having such a shape, when the width of the other convex portions is increased, a convex portion having a width similar to that of the convex portion closer to the base 133a (approximately the same width as the base 133a when viewed from the Z direction) can be provided. In other words, the width of the protrusions increases and then gradually decreases, so that the width of each of the multiple protrusions can be made substantially the same as the width of base 133a.

[0048] 2, it is possible to bring each roof portion 132f into contact with a single stopper 133 by adjusting the amount of rotation of the single stopper 133. In other words, when it is desired to bring the underside of the stopper 133 into contact with the roof portion 132f1, the convex portion of the stopper 133 protrudes from the wall portion 131b in the X direction, so that the stopper 133 can come into contact with the roof portion 132f1 while avoiding contact with the roof portion 132f2.

[0049] 5 is a diagram showing an example of the configuration of the charged particle beam device in the first embodiment when a sample 140 is placed on the sample 140. In the FIB-SEM device 100, the ion beam 111 irradiated from the FIB column 110 may be irradiated substantially parallel to the surface of the sample 140 placed on the jig 130. For example, when the tilt angle θ132 of the sample fixing part 132 is set to 45 degrees, the FIB column 110 irradiates the ion beam 111 from a position tilted 45 degrees from the Z axis.

[0050] The ion beam 111 emitted from the FIB column 110 converges to a single point. In other words, the ion beam 111 has a cone shape with the focal point as its apex, and has a beam width in areas other than the focal point. This beam width is called the unfocused portion of the ion beam 111.

[0051] When the ion beam 111 emitted from the FIB column 110 is irradiated substantially parallel to the surface of the sample 140 placed on the jig 130, the unfocused portion of the ion beam 111 is also irradiated to the sample. Therefore, the ion beam 111 processes the sample 140 so as to be slightly tilted in the depth direction with respect to the surface of the sample. That is, at the irradiated portion of the sample 140 with the ion beam 111, a structure having different depths depending on the location can be observed. This makes it possible to observe, for example, a pattern shape and a laminated film in the depth direction of the sample 140 by irradiating the ion beam 111 once. When the portion to be observed in the sample has a structure in which thin films are laminated or a relatively shallow hole pattern, the ion beam 111 is irradiated substantially parallel to the surface of the sample using the jig 130, so that the structure of the thin film can be observed in detail.

[0052] 6, 7, and 8 are diagrams showing an example of the angle adjustment operation of the sample 140 using the jig 130 in the first embodiment. FIG. 6-8(A) is a diagram of the jig 130 seen from the X direction. FIG. 6-8(B) is a diagram of the jig 130 seen from the Y direction. FIG. 6-8(C) is a diagram of the jig 130 seen from the Z direction. Note that in FIG. 6-8, the elements described above are omitted as appropriate.

[0053] Fig. 6 shows the jig 130 holding the sample fixing portion 132 in the initial position. The sample fixing portion 132 does not have to be in contact with the stopper 133. For example, in the jig 130 in the state shown in Fig. 6, the sample 140 is placed on the sample support surface 132a.

[0054] FIG. 7 shows a state where the sample fixing part 132 has been rotated by one step. That is, FIG. 7 shows a state where the sample fixing part 132 has been rotated until the roof part 132f2-α comes into contact with the lower surface of the stopper 133, and then the rotation of the sample fixing part 132 is stopped while maintaining that state. The sample fixing part 132 rotates by the inclination angle θ2α shown in FIG. 6, comes into contact with the lower surface of the stopper 133, and stops rotating. After the rotation of the sample fixing part 132 stops, the fixing part 131d provided on the wall part 131b is rotated until one end of the fixing part 131d comes into contact with the rotation shaft 132d inside the wall part 131b, thereby tightening the sample fixing part 132. As a result, the fixing part 131d fixes the sample fixing part 132 at the position after rotation.

[0055] When the sample 140 is placed on the jig 130, the sample 140 also tilts in accordance with the rotation of the sample holder 132, and the angle with respect to the irradiation direction of the ion beam 111 changes.

[0056] FIG. 8 shows a state where the sample fixing part 132 is rotated in two stages. That is, FIG. 8 shows a state where the sample fixing part 132 is rotated until the roof part 132f1-α comes into contact with the lower surface of the stopper 133, and then the rotation of the sample fixing part 132 is stopped while maintaining that state. The sample fixing part 132 rotates by the inclination angle θ1α shown in FIG. 6, comes into contact with the lower surface of the stopper 133, and stops rotating. After the rotation of the sample fixing part 132 stops, the fixing part 131d provided on the wall part 131b is rotated until one end of the fixing part 131d comes into contact with the rotation shaft 132d inside the wall part 131b, thereby tightening the sample fixing part 132. As a result, the fixing part 131d fixes the sample fixing part 132 at the position after rotation.

[0057] When the sample 140 is placed on the jig 130, the sample 140 also tilts in accordance with the rotation of the sample holder 132, and the angle with respect to the irradiation direction of the ion beam 111 changes.

[0058] Next, a sample processing method using the jig 130 will be described.

[0059] FIG. 9 is a flow chart showing an example of the sample processing method according to the first embodiment.

[0060] First, the sample 140 is placed on the sample support surface 132a of the sample fixing portion 132 of the jig 130. At this time, at least one side of the sample 140 may be supported by a step 132c. After the sample 140 is placed on the sample support surface 132a, the sample 140 is fixed by the sample support portion 132b (S10).

[0061] After the sample 140 is fixed to the sample fixing part 132, the sample fixing part 132 is rotated with respect to the wall part 131b about the rotation axis 132d (S20). The sample fixing part 132 may rotate clockwise or counterclockwise about the X direction.

[0062] As described in FIG. 6-8, the sample fixing part 132 is rotated until the lower surface of the stopper 133 comes into contact with the roof part 132f. This adjusts the angle of the sample 140 relative to the irradiation direction of the ion beam 111 to a predetermined angle. At this time, the rotation angle of the sample fixing part 132 can be determined by the stopper 133 provided on the upper surface of the wall part 131b in the Z direction. More specifically, when the sample fixing part 132 is rotated around the rotation axis 132d, the roof part 132f of the sample fixing part 132 comes into contact with the lower surface of the stopper 133. When the lower surface of the stopper 133 comes into contact with the roof part 132f, the rotation of the sample fixing part 132 is stopped (S30). That is, by appropriately setting the inclination angle of the roof part 132f, the rotation angle of the sample fixing part 132 can be adjusted to be within a desired range. For example, the inclination angle of the roof portion 132f may be changed to an appropriate angle by the operator. For example, when the roof portion 132f2 and the lower surface of the stopper 133 come into contact with each other, the sample fixing portion 132 may be inclined by 5 degrees compared to the state in which the sample fixing portion 132 is held in the initial position. In this case, the inclination angle θ2α of the roof portion 132f is 5 degrees. Also, for example, when the roof portion 132f1 and the lower surface of the stopper 133 come into contact with each other, the sample fixing portion 132 may be inclined by 10 degrees compared to the state in which the sample fixing portion 132 is held in the initial position. In this case, the inclination angle θ1α of the roof portion 132f is 10 degrees. In this way, the operator using the jig 130 may change the inclination angle of the roof portion 132f and the number of the roof portions 132f depending on the angle at which the sample is to be inclined.

[0063] After the lower surface of the stopper 133 comes into contact with the roof portion 132f and the rotation of the sample fixing portion 132 stops, the sample fixing portion 132 is fixed by the fixing portion 131d so that the sample fixing portion 132 does not move from the position after the rotation (S40). After the rotation of the sample fixing portion 132 stops, the fixing portion 131d provided on the wall portion 131b is rotated until one end of the fixing portion 131d comes into contact with the rotation shaft 132d inside the wall portion 131b, thereby tightening the sample fixing portion 132.

[0064] After the rotation of the sample fixing part 132 is stopped and fixed at a predetermined position, the ion beam 111 is irradiated from the FIB column 110 to process the sample 140 (S50). If the stopper 133 protruding from the wall part 131b in the XY plane is present between the ion beam 111 and the sample 140, the stopper 133 may obstruct the incidence of the ion beam 111 on the sample 140. If the stopper 133 overlaps with the trajectory of the ion beam 111, the stopper 133 may be returned to the initial position after the sample fixing part 132 is fixed by the fixing part 131d. In other words, after the rotation of the sample fixing part 132 is stopped by the stopper 133 and the sample fixing part 132 is fixed by the fixing part 131d, the stopper 133 may be returned to the initial position, that is, the upper surface of the wall part 131b in the Z direction, when the ion beam 111 is irradiated from the FIB column 110.

[0065] After a given portion of a sample 140 is processed by irradiating it with an ion beam 111 from an FIB column 110 , the processed surface of the sample 140 is observed using an SEM column 120 .

[0066] The roof portion 132f that comes into contact with the stopper 133 may be in contact with most of the roof portion 132f, or more than half of the roof portion 132f, or only one point or a portion of the roof portion 132f may come into contact with the stopper 133.

[0067] In a charged particle beam device, in order to prevent curtaining, when a sample is placed on a jig, the angle of the surface of the sample that has the portion to be observed relative to the irradiation direction of the ion beam is adjusted. The adjustment of the tilt angle of the sample when placed on the jig is usually performed by an operator. The operator tilts the sample by eye based on experience and fixes it to the jig with carbon tape or the like. As a result, the tilt angle of the sample placed on the jig can vary depending on the operator.

[0068] The jig 130 of the first embodiment has the sample fixing part 132 and a rotation mechanism, so that the sample can be easily tilted. Furthermore, by setting the tilt angle of the roof part 132f in advance, the rotation position can be accurately made to correspond to the set angle. In other words, when the sample is replaced and a new sample is placed on the jig 130 and the sample fixing part 132 is rotated, it is possible to make the tilt angle the same as that of the sample previously placed. This allows the tilt angle of the sample placed on the jig, which may vary depending on the operator, to be uniform by using the jig 130.

[0069] Furthermore, the tilt angle of the sample may be calculated in advance so that the incident direction of the ion beam 111 does not overlap with the structural pattern in the sample. By setting the tilt angle of the roof portion 132f according to the calculated tilt angle of the sample, the reproducibility of the angle adjustment is improved compared to the case where the operator fixes the sample to the jig with carbon tape or the like. That is, by using the jig 130 of this embodiment, it is possible to avoid a state in which, for example, the incident direction of the ion beam 111 overlaps with the structural pattern in the sample 140 when the sample 140 is viewed from the X direction. That is, it is possible to easily realize a state in which the ion beam 111 is irradiated from an inclined direction on the surface of the sample 140 (a state in which the incident direction of the ion beam 111 does not overlap with the structural pattern in the sample and curtaining is unlikely to occur). In addition, it is possible to improve the reproducibility of that state. That is, even if the sample placed on the jig 130 is replaced, the angle between the incident direction of the ion beam 111 with respect to the surface of the sample and the structural pattern in the sample can be kept constant.

[0070] (Modification) Fig. 10 is a diagram showing a configuration example of a jig 130 in a modified example of the first embodiment, and Fig. 11 is a top view showing the configuration example of the jig 130 in the modified example of the first embodiment.

[0071] In this modification, when the sample fixing part 132 is viewed from the X direction, a roof part 132f is provided that is inclined like a roof from the center of the arc part 132e. In other words, the roof part 132f does not have to be parallel to the upper surface of the wall part 131b in the support part 131. The roof part 132f is inclined so that the center of the circle is closest to the upper surface of the wall part 131b and gradually moves away from the upper surface of the wall part 131b. In other words, the roof part 132f is the upper surface of the sample fixing part 132 that is inclined from the center of the circle toward the floor part 131a. At this time, three roof parts 132f are provided in the jig 130 of FIG. 10 and FIG. 11, such as 132f1, 132f2, and 132f3. In addition to the shoulder part 132g1 and the shoulder part 132g2 described above, a shoulder part 132g3 is provided between the roof part 132f2 and the roof part 132f3.

[0072] For example, the sample-fixing portion 132 may be processed from a semicircular shape having an arc portion 132e to a shape having multiple shoulder portions 132g by cutting the end portion. The extension lines of the roof portion 132f may or may not overlap with the center of the arc portion 132e.

[0073] The roof portion 132f that comes into contact with the stopper 133 may be in contact with most of the roof portion 132f, or more than half of the roof portion 132f, or may be in contact with the stopper 133 at one point or a part of the roof portion 132f. For example, the rotation of the sample fixing part 132 may be stopped when at least the shoulder portion 132g comes into contact with the lower surface of the stopper 133.

[0074] The roof portion 132f3 has, for example, a roof portion 132f3-α and a roof portion 132f3-β. The roof portion 132f has α and β, respectively. When the sample fixing portion 132 is viewed from the X direction, the rotation angle of the sample fixing portion 132 from the state where the sample placement portion 132h and the rotation shaft 132d are held in the initial position until the stopper 133 described later and the roof portion 132f3 come into contact with each other is an inclination angle θ3α or θ3β.

[0075] The inclination angles θ3α and θ3β of the roof portions 132f3-α and 132f3-β may be the same or different.

[0076] Stopper 133 of this modification has two protrusions to match the three roof portions 132f. As a result, even if there are multiple roof portions 132f, such as roof portions 132f1, 132f2, and 132f3 in Fig. 11, it is possible to bring each roof portion 132f into contact with a single stopper 133 by adjusting the amount of rotation of the single stopper 133.

[0077] Other configurations and operations of this modified example may be the same as those of the first embodiment. Even with the configuration of this modified example, the same effects as those of the first embodiment can be obtained. Furthermore, the number of roof portions 132f can be determined by the operator, and any number of roof portions may be provided. Furthermore, the number of stoppers 133 or the convex portions of the stoppers 133 can be determined by the operator, and any number of roof portions may be provided.

[0078] Second embodiment 12 is a top view showing an example of the configuration of the jig 130 in the second embodiment. In the second embodiment, the jig 130 has a plurality of stoppers 133 each having an arc shape.

[0079] For example, when multiple roof portions 132f are provided, stopper 133 may be provided for each roof portion 132f. In other words, there may be multiple stoppers 133, such as stopper 133a provided corresponding to roof portion 132f1 and stopper 133b provided corresponding to roof portion 132f2.

[0080] The stopper 133 is provided on the upper surface of the wall portion 131b in the Z direction. The stopper 133 is fixed to the upper surface of the wall portion 131b so as to be rotatable in the XY plane. The tip of the stopper 133 can protrude from the wall portion 131b in the XY plane when viewed from the Z direction. When the sample fixing portion 132 is rotated with the stopper 133 protruding from the wall portion 131b, the roof portion 132f comes into contact with the lower surface of the stopper 133.

[0081] The centers of the arc-shaped stoppers 133a and 133b may coincide with the center of the upper surface of the wall portion 131b in the Z direction, for example.

[0082] Other configurations and operations of the second embodiment may be similar to those of the first embodiment. Even with the configuration of the second embodiment, the same effects as those of the first embodiment can be obtained. In addition, the stoppers 133 may be provided in accordance with the number of roof portions 132f, and multiple stoppers 133 may be provided.

[0083] Third embodiment 13 is a top view showing a configuration example of the jig 130 in the third embodiment. In the third embodiment, the jig 130 has one or more stoppers 133 each having a quadrilateral shape.

[0084] For example, when a plurality of roof portions 132f are provided, stopper 133 may be provided for each of α and β of roof portion 132f. In other words, a plurality of stoppers 133 may be provided, such as stopper 133a provided corresponding to roof portion 132f1-α, stopper 133b provided corresponding to roof portion 132f1-β, stopper 133c provided corresponding to roof portion 132f2-α, and stopper 133d provided corresponding to roof portion 132f2-β.

[0085] The stopper 133 is provided on the upper surface of the wall portion 131b in the Z direction. The stopper 133 is fixed to the upper surface of the wall portion 131b. When viewed from the Z direction, the stopper 133 can protrude from the wall portion 131b in the XY plane. When the sample fixing portion 132 is rotated with the stopper 133 protruding from the wall portion 131b, the roof portion 132f comes into contact with the lower surface of the stopper 133.

[0086] The stopper 133 may be provided in accordance with the number of roof portions 132f, and multiple stoppers may be provided. The stopper 133 can be removed from the wall portion 131b or moved so as to slide on the upper surface of the wall portion 131b, and can be moved to a position corresponding to the roof portion 132f where the stopper 133 is to be brought into contact. In other words, by providing one movable stopper 133 on the upper surface of the wall portion 131b, the installation position of the stopper 133 can be changed according to the position of the roof portion 132f where the stopper 133 is to be brought into contact. In this case, the number of stoppers 133 can be reduced. Furthermore, there is no need to change the shape of the stopper 133 according to the roof portion 132f.

[0087] When the stoppers 133 are removable and movable on the upper surface of the wall portion 131b, the stoppers 133 may be provided separately on the left and right sides (α and β) of the roof portion 132f.

[0088] Other configurations and operations of the third embodiment may be similar to those of the first embodiment. Even with the configuration of the third embodiment, the same effects as those of the first embodiment can be obtained. The stoppers 133 may be provided in accordance with the number of roof portions 132f, and multiple stoppers may be provided. In addition, the shape of the stoppers 133 is not limited to a quadrilateral shape, and may be, for example, a triangular shape.

[0089] (Fourth embodiment) Fig. 14 is an enlarged view of an example of a cross-sectional view of a sample 140 in the fourth embodiment. Fig. 15 is an enlarged view of an example of a cross-sectional view or a top view of a sample 140 during and after irradiation with an ion beam 111 in the fourth embodiment.

[0090] FIG. 14 is an example of a cross-sectional view of a sample 140 that is a semiconductor sample in the fourth embodiment. In the sample 140, a laminated film 144 is formed by alternately laminating a silicon oxide film 142 and a silicon nitride film 143 on a substrate 141. When a hole 146 such as a memory hole or a contact hole is provided in the sample 140, a mask 145 having a shape corresponding to the hole 146 is provided on the laminated film 144. When etching is performed on the sample 140 in this state to form a pattern, as the laminated film 144 is processed and the hole 146 extends downward, a deposit 145α accumulates on the side of the mask 145. Note that the hole 146 in the following description includes not only the hole in the laminated film 144 but also the hole in the mask.

[0091] If the deposit 145α accumulates on the sides of the mask 145, the shape of the hole 146 may be affected. For example, the amount of etching to the bottom of the hole 146 may decrease, causing the hole 146 to taper as it gets deeper.

[0092] It is necessary to accurately inspect the shape of the hole 146 at different points to see how the diameter of the hole 146 changes in the depth direction. When inspecting whether the diameter of the hole 146 is uniform in the depth direction, by using the jig 130 of the present invention, the sample 140 can be cut by the ion beam 111 from the FIB column 110 and observed by the SEM column 120.

[0093] Fig. 15A is a diagram showing an example of a cross-sectional view of the sample 140 when irradiated with the ion beam 111 in the fourth embodiment. Fig. 15B is a diagram showing an example of a cross-sectional view of the sample 140 after irradiating with the ion beam 111 in the fourth embodiment. Fig. 15C is a diagram showing an example of a top view of the sample 140 after irradiating with the ion beam 111 in the fourth embodiment, and is a top view of a hole 146 in the sample 140 after being processed by irradiating with the ion beam 111.

[0094] As shown in FIG. 15A, the ion beam 111 irradiated from the FIB column 110 may be irradiated so that the central axis 111c is approximately parallel to the surface of the sample 140 placed on the jig 130. In FIG. 15A, the ion beam 111 is irradiated so that the central axis 111c is approximately parallel to the surface of the sample 140 placed on the jig 130. The FIB column 110 focuses the ion beam 111 toward one point. In other words, the ion beam 111 has a cone shape with the focal point as the apex, and has a beam width, that is, an unfocused portion, at a location other than the focal point. Therefore, when a location of the sample 140 far from the FIB column 110 is set as the focal point of the ion beam 111, the sample 140 is processed along the shape of the ion beam 111 in the middle of focusing (along the beam width).

[0095] Fig. 15B is a diagram showing the state when the irradiation of the ion beam 111 onto the surface of the sample 140 shown in Fig. 15A is completed. As described above, the height from the bottom surface of the sample 140 to the top surface of the sample 140 varies according to the shape of the ion beam 111 in the process of being focused.

[0096] 15B and 15C are measured by observing the surface of sample 140 with SEM column 120, the diameters D1 to D5 of holes 146 on the surface of sample 140 are compared. As a result, by irradiating ion beam 112 once, diameters D1 to D5 of holes 146 at different positions in the depth direction can be measured.

[0097] When it is desired to inspect the change in diameter of hole 146 in the depth direction, it is possible to perform measurement by scraping sample 140 so that the cross section can be seen, as shown in Figure 14. However, when observing the cross section of sample 140, the diameter of hole 146 is very small, and it is difficult to match the cross section with the diameter of hole 146.

[0098] 16 is a top view showing an example of hole 146 having diameter D1 in the fourth embodiment. The diameter of hole 146 to be measured is D1, but when sample 140 is scraped so that the cross section is visible, the diameter of hole 146 in the cross section may be D'1.

[0099] In this case, the surface of the sample 140 is scraped, and the processed surface of the sample 140 after scraping is observed by SEM, so that the diameter of the hole 146 can be easily determined from the processed surface. Therefore, the change in the pattern shape in the depth direction of the sample 140 can be accurately inspected.

[0100] In addition, the jig 130 used in this embodiment can set the tilt angle of the sample 140 by the sample fixing part 132 and the stopper 133. For example, if an operator manually adjusts the tilt angle of the sample and repeatedly places multiple samples of the same type as the sample 140, the tilt angles of the samples may differ greatly. In this case, the direction of the ion beam irradiated to the surface of the sample also differs every time the sample is placed. Therefore, when the ion beam 111 is obliquely incident on the sample surface, there is a possibility that the spacing of the patterns (e.g., multiple holes 146) will differ every time the sample is replaced. Furthermore, even for patterns (e.g., multiple holes 146) arranged at the same location on the same sample, the positions of the patterns exposed on the surface after processing of the sample in the depth direction may differ.

[0101] In contrast, by using the jig 130 of this embodiment, the inclination angle of the sample can be controlled by the sample fixing part 132 and the stopper 133. Therefore, even if the ion beam 111 is incident on the sample surface at an angle, the incident angle can be made uniform. That is, even if the sample is replaced, the intervals between patterns (e.g., a plurality of holes 146) are uniform, and even for patterns (e.g., a plurality of holes 146) arranged in the same place on the same sample, the positions in the depth direction of the patterns exposed on the surface after processing of the sample can be made uniform. Even when inspections of pattern formation are performed many times using the same multiple samples, it becomes possible to accurately compare the results with the previous or subsequent inspection results.

[0102] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0103] 100 FIB-SEM equipment 110 FIB Column 120 SEM column 130 Jig 131 Support part 131a Floor section 131b Wall section 131c support shaft 132d Fixation part 132 Sample Fixation Unit 132a Sample holding surface 132b Sample holder 132c Step 132d Rotating shaft 132e Arc section 132f Roof 132g shoulder 132h Sample placement area 133 Stopper 133a base 133b Tip (convex part)

Claims

1. A support portion having a wall portion extending in a first direction and a second direction perpendicular to the first direction; a rotatable sample fixing section having a sample holding surface on which a sample can be mounted and a sample holding mechanism; a stopper provided on an upper surface of the wall portion and coming into contact with the sample fixing part when the sample fixing part rotates; A jig having the above structure.

2. The sample fixing unit includes: a sample placement portion on which the sample support surface is formed and which has an arcuate portion when viewed from a third direction perpendicular to the first direction and the second direction; a rotation shaft extending in the third direction from the sample placement portion and penetrating the wall portion; The fixture of claim 1 further comprising:

3. The jig according to claim 2 , further comprising a fixing portion provided on a side surface of the wall portion of the support portion, contacting the rotating shaft inside the wall portion and fixing the rotating shaft.

4. The jig according to claim 2 , wherein the sample fixing portion further comprises a roof portion inclined from the center of the arc portion.

5. The jig according to claim 4 , wherein at least two or more roof portions are provided, and the two or more roof portions have different inclination angles from the center of the circle.

6. The jig according to claim 4 , wherein the stopper is rotatably provided on an upper surface of the wall portion of the support portion, and a lower surface of the stopper comes into contact with any of the roof portions of the sample fixing portion when the sample fixing portion rotates.

7. 5. The jig according to claim 4, wherein when the sample fixing portion has n roof portions (n ​​is a natural number), the stopper has n-1 convex portions.

8. The jig of claim 4 , wherein the stopper is semi-arc shaped.

9. The jig according to claim 4 , wherein a plurality of the stoppers are provided corresponding to the number and positions of the roof portions of the sample fixing portion.

10. The jig according to claim 1 , wherein the stopper is protrudible from an initial position on the upper surface of the wall portion.

11. The jig according to claim 1 , wherein the sample fixing portion further comprises a step provided on the sample holding surface, the step being capable of fixing at least one side of the sample.

12. 2. The jig according to claim 1, wherein when the sample fixing portion is in an initial position, the sample support surface is inclined so as to form an acute angle with a normal direction of the wall portion when viewed from the second direction.

13. preparing a jig having a sample fixing part on which a sample can be placed and which is rotatable around a rotation axis, and a stopper which comes into contact with the sample fixing part; The sample is fixed to a sample fixing part; Rotating the sample fixing part around the rotation axis; When the upper surface of the sample fixing part and the lower surface of the stopper come into contact with each other, the rotation of the sample fixing part is stopped. The jig is attached to a sample processing device; Sample processing methods.

14. After mounting on the sample processing device, irradiating the sample with a charged particle beam to process it; The sample processing method according to claim 13.

Images