Sample cartridge and charged particle beam device

Abstract

The present invention provides a sample cartridge that has a simple structure and can be manufactured at a low cost, and a charged particle beam device in which the sample cartridge is fixed on a stage in order to observe a sample. As a means to this end, a sample cartridge that is conveyed, inserted in a charged particle beam device, and used in sample observation is employed, and the sample cartridge includes the following: a sample table on which a sample can be placed; a rotation mechanism for rotating the sample table with a first direction which is the longitudinal direction of the sample cartridge serving as the axis of rotation; and an inclination mechanism that rotates and inclines the sample table with a second direction orthogonal to the first direction in a plan view serving as the axis of rotation.

Description

Sample cartridge and charged particle beam device

[0001] The present invention relates to a sample cartridge that carries a sample to be observed and is transported by a transport device, and a charged particle beam device that fixes the sample cartridge, detached from the transport device, on a stage to observe the sample.

[0002] Charged particle beam instruments such as transmission electron microscopes (TEMs) and scanning electron microscopes (SEMs) are well-known as instruments for observing samples. TEM specimen observation generally uses a specimen holder, but observing multiple specimens requires manual replacement of specimen holders (specimen cartridges). Therefore, continuous observation of a large number of specimens can be cumbersome.

[0003] Non-Patent Document 1 describes a two-axis tilt cartridge in which the sample stage at the tip of the sample cartridge can be tilted about two axes oblique to the longitudinal direction of the cartridge as rotation axes.

[0004] “High-stability, Highly Automated Double-eucentric (S)TEM Sample Stage”, Microscopy and Microanalysis, (US), 1 August 2006, Volume 12, Issue S02, Pages 1104-1105, Published: 31 July 2006

[0005] The structure of the biaxial tilt cartridge described in Non-Patent Document 1 is complicated.

[0006] An object of the present invention is to provide a sample cartridge that has a simple structure and can be manufactured at low cost, and a charged particle beam instrument for observing a sample by fixing the sample cartridge on a stage.

[0007] A brief summary of a representative embodiment of the present invention will be given below.

[0008] In one embodiment, the sample cartridge is transported and inserted into a charged particle beam device for use in sample observation, and includes a sample stage on which a sample can be placed, a rotation mechanism that rotates the sample stage around a first direction that is the longitudinal direction of the sample cartridge as a rotation axis, and a tilt mechanism that rotates and tilts the sample stage around a second direction that is perpendicular to the first direction in a plan view.

[0009] According to the present invention, it is possible to provide a sample cartridge that has a simple structure and can be manufactured at low cost, and a charged particle beam device in which the sample cartridge is fixed on a stage and a sample is observed.

[0010] The sample cartridge of the present invention is mounted on a stage in a sample chamber of a charged particle beam device, and the stage is mounted on the stage.

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all drawings for explaining the embodiments, components having the same functions are designated by the same reference numerals, and repeated explanations thereof will be omitted. In addition, in the embodiments, explanations of the same or similar parts will not be repeated unless particularly necessary.

[0012] The X direction (X axis) and the Y direction (Y axis) are perpendicular to each other in a plan view and are both directions along a horizontal plane. Here, the direction perpendicular to the X and Y directions is called the Z direction (Z axis) or the up-down direction.

[0013] In a charged particle beam device, in order to obtain a correct image of a sample, it is necessary to tilt the sample to align its crystal orientation. Also, in some cases, it is necessary to tilt the sample to obtain 3D data. Furthermore, sample cartridges are exchanged to observe multiple samples. In the following embodiments, a sample cartridge equipped with a mechanism for tilting the sample in each of two axes, a stage on which this sample cartridge is mounted, and a charged particle beam device are described.

[0014] (Embodiment) An example of an electron microscope will be described below as an embodiment. An apparatus equipped with a removable sample cartridge according to this embodiment is applicable to charged particle beam devices such as a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). Here, a transmission electron microscope will be used as an example. FIG. 1 is a schematic side view showing a state in which a sample cartridge according to this embodiment is placed on a stage in a sample chamber of a charged particle beam device (electron microscope).

[0015] FIG. 1 shows a charged particle beam device 100 according to the present embodiment. The charged particle beam device 100 has a substantially cylindrical lens barrel 1 that extends in the Z direction and has radial directions in the X and Y directions. Arranged within the lens barrel 1, from top to bottom, are an electron gun 2, an electron optical system 3 (e.g., an illumination system lens such as a condenser lens), and an imaging system 5 (e.g., an objective lens, an intermediate lens, a projection lens, etc.). A detector 4 is disposed at a height between the electron optical system 3 and the imaging system 5. A stage 8 is disposed below the imaging system 5, on whose top a sample cartridge used for sample observation can be fixed.

[0016] Below the stage 8, an imaging system 5 and an electron optical system 3, which are different from those described above, are arranged in this order, and below them is a fluorescent screen 6. Within the microscope barrel 1, a camera (fluorescent screen detector array, imaging unit) 7 is arranged near the fluorescent screen 6 to capture an image of the upper surface of the fluorescent screen 6.

[0017] In Figure 1, a sample cartridge 10 is fixed by a holding mechanism 11 on a stage 8. The sample cartridge 10 is transported in the X direction by a transport device 9 provided outside the lens barrel 1, and can be inserted into or removed from the lens barrel 1. Insertion and removal as used herein refers to inserting the sample cartridge 10 into the lens barrel 1 or removing it from inside the lens barrel 1 to the outside. The sample cartridge 10 can also be automatically replaced using the transport device (transport unit, transport means) 9. The sample cartridge 10 transported into the lens barrel 1 is held on the stage 8 by the holding mechanism 11.

[0018] The sample cartridge 10 has a rod-like structure extending in the X direction, and is inserted into and removed from the sample chamber of the microscope column 1. A sample 20 is placed on the tip of the sample cartridge 10. The sample 20 is, for example, a sample of carbon black or a semiconductor wafer.

[0019] The electron beam generated by the electron gun 2 is converged by the electron optical system 3 and the imaging system 5 and irradiated onto the sample 20. Secondary electrons emitted from the sample 20 when the surface of the sample 20 is irradiated with the electron beam are detected by the detector 4. This makes it possible to grasp the shape of the top surface of the sample 20.

[0020] The electron beam transmitted through the sample 20 is imaged by the imaging system 5 and magnified by the electron optical system 3. The magnified transmission image of the sample 20 is projected onto the upper surface of the fluorescent screen 6. The transmission image projected onto the fluorescent screen 6 is captured by the camera 7 and stored in a computer external to the electron microscope column 1. This results in a transmission image (high-magnification image (magnified image)) or electron diffraction pattern (diffraction spots) projected onto the fluorescent screen 6 by the electron beam transmitted through the sample 20. By observing the transmission image (transmitted electrons), it is possible to obtain information such as the particle shape, crystal lattice, or electron diffraction inside the sample.

[0021] 2 is a plan view showing the state in which the sample cartridge 10 of this embodiment is placed on the stage 8. The sample cartridge 10 is placed on the stage 8 separate from the transport device 9. In other words, the sample cartridge 10 can be inserted into and removed from the stage 8.

[0022] The longitudinal direction of the sample cartridge 10 extends in the X direction. The stage 8 extends in the X-Y plane along the X and Y directions, and has a donut-shaped structure with a through-hole in the center. Although not shown in FIG. 2, the sample cartridge 10 is held by a holding mechanism 11 (see FIG. 1) provided on the upper surface of the stage 8. In FIG. 2, the sample cartridge 10 (here, including the sample 20), which is a part that can be inserted into and removed from the microscope column 1 (see FIG. 1), is hatched.

[0023] The sample cartridge 10 has a tilting mechanism 17 that can be pushed in in the X direction and slides inside the sample cartridge 10. The tilting mechanism 17 has a rod-shaped structure extending in the X direction, with one end exposed as part of the exterior of the sample cartridge 10. The sample cartridge 10 also has a cylindrical rotation mechanism (drive mechanism) 13 that extends in the X direction, and a cartridge rotation unit 10A (see FIG. 3 ) that passes inside the rotation mechanism 13 and extends in the X direction. The cartridge rotation unit 10A has a sample stage 19 and the tilting mechanism 17. The sample cartridge 10 also has a rotation pin 15 that is fixed to the cartridge rotation unit 10A located within the rotation mechanism 13 and is rotatable around the X axis. The rotation pin 15 protrudes outside the rotation mechanism 13, for example, in the Z direction.

[0024] Stage 8 is provided, at its upper portion, with rotating section 14A that is rotatable around fulcrum section 14B, and rotating section 18A that is rotatable around fulcrum section 18B. Stage 8 also is provided, at its upper portion, with contact section 14C that is part of rotating section 14A, and rectilinear section 14D that is pushed by contact section 14C and is capable of sliding in the Y direction. The rotation axes of rotating sections 14A and 18A are aligned along the Z direction, and rotating sections 14A and 18A each rotate in a direction along the XY plane.

[0025] Rotating unit 14A is rotated by drive mechanism 12, which can be operated from outside of lens barrel 1, and rotating unit 18A is rotated by drive mechanism 16, which can be operated from outside of lens barrel 1. Drive mechanisms 12 and 16 reciprocate in their respective extension directions, which are along the XY plane. When drive mechanisms 12 and 16 move in their respective extension directions, rotating units 14A and 18A rotate.

[0026] Here, rotating the sample cartridge 10 around a rotation axis extending in the X direction is referred to as α rotation. When rotating the sample cartridge 10 by α, the following operation is performed. That is, a drive mechanism 12 operated from outside the microscope barrel 1 pushes a rotation pin 15 on the sample cartridge 10 via a rotation drive mechanism (rotation transmission mechanism, rotation transmission mechanism) 14, thereby rotating the sample cartridge 10 by α. The rotation drive mechanism 14 has, for example, a rotation portion 14A, a fulcrum portion 14B, a contact portion 14C, and a linear portion 14D.

[0027] In other words, when the drive mechanism 12 pushes one end of the rotating portion 14A, the rotating portion 14A rotates around the fulcrum portion 14B on the opposite side of the rotating portion 14A. As the rotating portion 14A moves, the contact portion 14C pushes or pulls the linear portion 14D. This moves the linear portion 14D in the Y direction. The contact portion 14C only contacts the linear portion 14D, but is not connected to it. As the drive mechanism 12 is pushed toward the center of the lens barrel 1, the linear portion 14D indirectly moves downward in FIG. 2 . In contrast, the linear portion 14D is biased upward in FIG. 2 by an elastic portion such as a spring. Therefore, as the drive mechanism 12 moves outward from the lens barrel 1, the rotating portion 14A rotates, and the linear portion 14D moves upward in FIG. 2 .

[0028] The movement of the straight-moving section 14D moves the rotation pin 15 (α rotation), which causes the rotation mechanism 13 of the sample cartridge 10 to rotate the cartridge rotation section 10A (α rotation). In other words, the rotation mechanism 13 rotates the sample stage 19. The rotation drive mechanism 14 is separated from the sample cartridge 10 and is provided on the stage 8 (charged particle beam device). The rotation mechanism 13 rotates the sample stage 19 by being operated (driven) by the rotation drive mechanism 14.

[0029] Furthermore, here, rotating the sample stage 19 provided on the sample cartridge 10 around a rotation axis extending in the Y direction is referred to as β rotation. When rotating the sample stage 19 β, the following operation is performed. That is, a drive mechanism 16 operated from outside the electron tube 1 pushes a tilt mechanism 17 provided on the sample cartridge 10 via a tilt transmission mechanism 18, thereby rotating the sample stage 19 at the tip of the sample cartridge 10 β. The tilt transmission mechanism 18 is separated from the sample cartridge 10 and is provided on the stage 8 (charged particle beam device). The tilt mechanism 17 is operated (driven) by the tilt transmission mechanism 18 to tilt the sample stage 19.

[0030] Figure 3 is a cross-sectional view of the sample cartridge 10 of this embodiment. As shown in Figure 3, the tilting mechanism 17 includes link tilting mechanisms 17A, 17B, and 17C. The sample cartridge 10 includes a cartridge rotating section 10A, a sample stage (tip sample stage) 19, a rotation mechanism 13, and a tilting mechanism 17. The sample cartridge 10 extends in the X direction and includes the sample stage 19, on which a sample can be placed, at one end in the direction of extension, and the cartridge rotating section 10A at the rear end opposite the end. The cartridge rotating section 10A contacts the rotation mechanism 13 on the outside and includes the tilting mechanism 17 on its inside.

[0031] Here, a spring (not shown) is provided that biases the link tilt mechanism 17A in a direction that pushes the link tilt mechanism 17A outward from the sample cartridge 10 (to the right in FIG. 3 ). The link tilt mechanisms 17A and 17B may be rotatably connected to each other. The link tilt mechanisms 17B and 17C may be rotatably connected to each other. The link tilt mechanism 17C and the sample stage 19 may be rotatably connected to each other. Alternatively, these may not be connected to each other, and the sample stage 19 may tilt in one direction (β rotation) when the link tilt mechanism 17A is pushed in, and the sample stage 19 may tilt in the other direction (β rotation) due to, for example, the force of a spring biased against the sample stage 19.

[0032] The rotation mechanism 13 includes, for example, a cylindrical rotating ring 13A surrounding the cartridge rotating part 10A, a rotating pin 15 fixed to the cartridge rotating part 10A, and a bearing 13B disposed between the cartridge rotating part 10A and the rotating ring 13A. The rotating ring 13A is fixed to the holding mechanism 11 (see FIG. 1 ) of the stage 8, thereby fixing the entire sample cartridge 10 to the stage 8. The cartridge rotating part 10A is supported by the bearing 13B between it and the rotating ring 13A. The force of the drive mechanism 12 indirectly presses the rotating pin 15, causing the cartridge rotating part 10A, tilting mechanism 17, and sample stage 19 to rotate relative to the rotating ring 13A, thereby performing α rotation. This allows the tilt angle of the surface of the sample 20 placed on the sample stage 19 to be adjusted around the X direction. Here, tilting the sample 20 around the X direction is referred to as α tilt. Tilting the sample 20 around the Y direction is referred to as β tilt.

[0033] The sample stage 19 achieves β tilt via link tilt mechanisms 17A, 17B, and 17C by operating the tilt mechanism 17 from outside the microscope barrel 1. The tilt mechanism 17 has, for example, link tilt mechanisms 17A, 17B, and 17C.

[0034] That is, by operating the drive mechanism 16 from outside the lens barrel 1, the link tilt mechanism 17C is driven in the X direction, either pushing in or pulling out, via the tilt transmission mechanism 18. When the link tilt mechanism 17C is driven and slides in the X direction, the link tilt mechanisms 17B and 17A are driven, which in turn drives the sample stage 19 connected to the link tilt mechanism 17A. This achieves β rotation (β tilt) of the sample stage 19. In FIG. 3, the support parts that enable the link tilt mechanisms 17A and 17B and the sample stage 19 to rotate around an axis along the Y direction are each indicated by a circle. These support parts are fixed to a support part (case) that is fixed to the cartridge rotation part 10A.

[0035] As described above, α rotation (α tilt) is achieved by rotating the sample cartridge 10 itself using the bearing 13B built into the sample cartridge 10. Furthermore, β tilt (β rotation) is achieved by tilting the sample stage 19 using the link tilt mechanisms 17A, 17B, and 17C built into the sample cartridge 10. In this manner, in this embodiment, rotation is achieved using the built-in bearings and link mechanisms, so the rotation mechanism and drive mechanism are simple in structure, and the sample cartridge can be manufactured at low cost. Furthermore, the sample cartridge can be easily replaced, transported, and controlled automatically.

[0036] Furthermore, here, the structure of the stage 8 described with reference to Figure 2 connects the rotation drive mechanism 14 and tilt transmission mechanism 18 of the sample cartridge 10 to the sample cartridge 10 on the plane of the stage 8, thereby achieving two-axis tilt for observation of the sample 20. This allows α rotation and β tilt to be achieved by separate, separate transmission mechanisms. Therefore, the structure of the rotation drive mechanism and tilt transmission mechanism on the stage is simple, allowing the stage to be manufactured at low cost. In addition, it is easy to accommodate automatic replacement, transportation, and control of the sample cartridge.

[0037] The invention made by the inventors has been specifically described above based on the embodiments thereof, but the present invention is not limited to the above embodiments and can be modified in various ways without departing from the spirit of the invention. For example, the above-described examples have been described in detail to clearly explain the technical content, and the invention is not necessarily limited to those having all of the described configurations. Furthermore, it is possible to add, delete, or replace part of the configuration of each example with other configurations.

[0038] For example, the rotation mechanism 13, the rotation drive mechanism 14, the tilt mechanism 17, and the tilt transmission mechanism 18 in the above-described embodiment are merely examples, and the present invention is not limited to the specific examples.

[0039] The present invention can be widely used in sample cartridges and charged particle beam devices in which the sample can be tilted.

[0040] REFERENCE SIGNS LIST 1 Column 2 Electron gun 3 Electron optical system 4 Detector 5 Imaging system 6 Fluorescent screen 7 Camera 8 Stage 9 Transport device 10 Sample cartridge 10A Cartridge rotation unit 11 Holding mechanism 12 Drive mechanism 13 Rotation mechanism 13A Rotating ring 13B Bearing 14 Rotation drive mechanism 14A Rotation unit 14B Support unit 14C Contact unit 14D Straight unit 15 Rotation pin 16 Drive mechanism 17 Tilt mechanism 17A, 17B, 17C Link tilt mechanism 18 Tilt transmission mechanism 18A Rotation unit 18B Support unit 19 Sample stage 20 Sample 100 Charged particle beam device

Claims

1. A sample cartridge that is transported and inserted into a charged particle beam apparatus and used for sample observation, A sample stand on which a sample can be placed, A cylindrical rotating ring whose central axis is the first direction, which is the longitudinal direction of the sample cartridge, A rotating part is disposed within the rotating ring and is supported by the rotating ring so as to be rotatable with respect to the first direction as the axis of rotation, A rotating pin is fixed to the rotating part and protrudes outward from the rotating ring, A tilting mechanism is provided within the rotating section, which rotates and tilts the sample stage with a second direction perpendicular to the first direction in a plan view as the axis of rotation, The tilting mechanism comprises a rod-shaped first link tilting mechanism extending in the first direction, It has, The sample cartridge has a rod-shaped structure extending in the first direction, The tilting mechanism rotates and tilts the sample stage with the second direction as the axis of rotation by sliding the first link tilting mechanism in the first direction. A sample cartridge in which the rotating part, the tilting mechanism, and the sample stage rotate around the first direction as the axis of rotation by pushing the rotating pin so that it rotates around the first direction as the axis of rotation.

2. In the sample cartridge according to claim 1, It has a bearing positioned between the rotating ring and the rotating part, A sample cartridge in which the rotation of the rotating part is supported by the bearing.

3. In the sample cartridge according to claim 1, A sample cartridge in which, when the sample cartridge is positioned on a stage within the charged particle beam apparatus, a rotation drive mechanism, provided separately from the sample cartridge, rotates the sample stage by pressing the rotation pin.

4. In the sample cartridge according to claim 1, The tilting mechanism is operated by a tilting drive mechanism, which is provided separately from the sample cartridge, when the sample cartridge is placed on the stage, thereby tilting the sample stage.

5. A charged particle beam apparatus comprising the sample cartridge described in claim 1.

6. In the charged particle beam apparatus according to claim 5, A stage on which the sample cartridge is placed, A rotational drive mechanism that drives the aforementioned rotational mechanism, A tilting drive mechanism that drives the aforementioned tilting mechanism, A charged particle beam device equipped with [a specific feature / technology].