Charged particle beam device

Abstract

Provided is a charged particle beam device which achieves both properties for both holding and attaching / detaching a sample cartridge. This charged particle beam device comprises: a charged particle generation unit that emit a charged particle beam; a sample stage into which a cartridge where a sample is placed is inserted; a lens group that converges or expands the charged particle beam; and a detector that detects the charged particle beam radiated onto the sample or the charged particles generated from the sample. The cartridge includes, from the insertion direction side thereof to the counter-insertion direction side thereof, a sample stage on which the sample is placed, a drag-generating surface, and a thrust-generating surface. The sample stage includes a cartridge holding part where the cartridge is mounted. The cartridge holding part has a thrust-applying member which applies, to the thrust-generating surface, thrust for moving the cartridge in the insertion direction, and a drag-applying member which applies, to the drag-generating surface, drag for moving the cartridge in the counter-insertion direction.

Description

Technical Field

[0001] The present invention relates to a charged particle beam apparatus in which a sample cartridge is mounted on a sample stage.

Background Art

[0002] As a document related to a sample cartridge of a charged particle beam apparatus, Patent Document 1 is known. For example, in paragraph 0016 of Patent Document 1, it is described that "the mounting portion 112 is provided at the tip of the shaft portion 102. The mounting portion 112 is configured to be able to mount the cartridge 150. The mounting portion 112 has a mounting surface 114 for mounting the cartridge 150. The mounting portion 112 has a leaf spring 116, and the cartridge 150 placed on the mounting surface 114 is pressed against the block 120 and the block 122 by the leaf spring 116. Thereby, the cartridge 150 is fixed."

[0003] Further, in paragraph 0017 of the same document, it is described that "the block 120 and the block 122 are members that contact the cartridge 150 when the cartridge 150 is placed on the mounting surface 114. The block 120 and the block 122 function as guides for guiding the cartridge 150 when attaching the cartridge 150 to the mounting portion 112."

[0004] Thus, the sample holder of Patent Document 1 includes a surface for placing the cartridge and two blocks that are pressed by a spring and serve as guides, and holds the cartridge by these blocks.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the sample holder of Patent Document 1, the cartridge is held in place solely by frictional force with the contact surface. Therefore, if the rigidity of the leaf spring is increased to enhance the frictional force in order to increase the holding force, the cartridge's ease of attachment and detachment deteriorates as a trade-off for the increased holding force.

[0007] Therefore, the object of the present invention is to provide a charged particle beam apparatus that achieves both cartridge retention force and ease of attachment and detachment. [Means for solving the problem]

[0008] To solve the above problems, one representative charged particle beam apparatus of the present invention is a charged particle beam apparatus comprising: a charged particle generating unit that irradiates a charged particle beam; a sample stage into which a cartridge on which a sample is placed is inserted; a lens group that focuses or amplifies the charged particle beam; and a detector that detects the charged particle beam irradiated onto the sample and charged particles generated from the sample, wherein the cartridge has a sample stand on which the sample is placed, a drag force generating surface, and a thrust force generating surface, extending from the insertion direction side to the opposite insertion direction; the sample stage has a cartridge holding unit into which the cartridge is mounted; and the cartridge holding unit has a thrust-applying member that applies thrust to the thrust-generating surface to move the cartridge in the insertion direction; and a drag-applying member that applies drag to the drag-generating surface to move the cartridge in the opposite insertion direction. [Effects of the Invention]

[0009] According to the charged particle beam apparatus of the present invention, it is possible to achieve both cartridge retention force and ease of attachment and detachment. [Brief explanation of the drawing]

[0010] [Figure 1] A schematic side view showing the overall configuration of a charged particle beam apparatus according to one embodiment. [Figure 2A] A side view of a cartridge in one embodiment. [Figure 2B]A top view of a cartridge in one embodiment. [Figure 2C] A front view of a cartridge according to one embodiment. [Figure 2D] Rear view of a cartridge in one embodiment. [Figure 3] Side view of the cartridge holder section with the cartridges shown in Figures 2A to 2D inserted. [Figure 4] Front view of the cartridge holder with cartridges inserted from Figure 2A to Figure 2D. [Modes for carrying out the invention]

[0011] Below, an embodiment of the charged particle beam apparatus of the present invention will be described using a transmission electron microscope that images a sample placed on a cartridge as an example.

[0012] <Charged Particle Beam Device 1> Figure 1 is a schematic side view showing the overall configuration of a charged particle beam apparatus 1 (transmission electron microscope) according to one embodiment of the present invention. As shown in the figure, the charged particle beam apparatus 1 comprises, from top to bottom, an electron gun 11 that irradiates an accelerated electron beam B, a microscope body 12, and a stand 13 that supports the electron gun 11 and the microscope body 12. Furthermore, it includes a main control unit 14 and a stage controller 15 that control the charged particle beam apparatus 1. Specifically, the main control unit 14 and the stage controller 15 are computers equipped with hardware such as a CPU or other computing device, a main memory device such as a semiconductor memory, an auxiliary storage device such as a hard disk, and a communication device. The computing device executes a predetermined program to realize the functions of the main control unit 14 and the stage controller 15, which will be described later. In the following description, such well-known technologies will be omitted as appropriate.

[0013] The inside of the microscope body 12 is equipped with, from top to bottom, an illumination lens 12a, an objective lens 12b, a sample stage 12e, an imaging lens 12c, and a detector 12d. An insertion section 12f for inserting a sample S is provided on the side of the microscope body 12, and after inserting the cartridge 2 into the sample stage 12e, the insertion section 12f can be closed to vacuum-seal the sample stage 12e. In addition, a cartridge holder section 3 for mounting the cartridge 2 is provided inside the sample stage 12e.

[0014] In the following, the insertion direction of cartridge 2 is defined as the X-axis, the horizontal direction perpendicular to the X-axis as the Y-axis, and the vertical direction as the Z-axis. Although not shown in the diagram, the sample stage 12e is equipped with a drive mechanism for moving the position of cartridge 2 in the X, Y, and Z axes, and for changing the orientation of cartridge 2 around the X, Y, and Z axes. By controlling the drive mechanism according to commands from the stage controller 15, the sample S on cartridge 2 inserted into the sample stage 12e can be set to the desired position and orientation.

[0015] To obtain an observation image of the sample S placed on cartridge 2, the charged particle beam apparatus 1 of this embodiment operates as follows. First, using an automatic loading device or the like, cartridge 2 on which the sample S is placed is inserted from the insertion section 12f into the sample stage 12e and attached to the cartridge holding section 3. Next, the stage controller 15 controls the drive mechanism of the sample stage 12e so that the sample S moves to the irradiation position of the electron beam B. Then, under the control of the main control unit 14, the electron beam B is irradiated from the electron gun 11 toward the microscope body 12. Inside the microscope body 12, the electron beam B is focused by the irradiation system lens 12a and the objective lens 12b and irradiated onto the sample S on cartridge 2. The electron beam B that has passed through the sample S is magnified by the imaging system lens 12c and then detected by the detector 12d. The electrical signal from the detector 12d is then taken up by the main control unit 14, and the sample S is imaged.

[0016] <Cartridge 2> Next, the shape of the cartridge 2 of this embodiment will be described using FIGS. 2A to 2D. Note that FIG. 2A is a side view of the cartridge 2, FIG. 2B is a top view of the cartridge 2, FIG. 2C is a front view of the cartridge 2, and FIG. 2D is a rear view of the cartridge 2.

[0017] As shown in these figures, the cartridge 2 is formed by connecting a substantially cylindrical portion on the negative X-axis side (anti-insertion direction side) and a plate-like portion on the positive X-axis side (insertion direction side). The substantially cylindrical portion includes a large-diameter portion on the positive X-axis side, a small-diameter portion on the negative X-axis side, and a tapered portion connecting the large-diameter portion and the small-diameter portion. Hereinafter, this tapered portion is referred to as the thrust generating surface 21. In addition, a notch is provided at the lower part on the positive X-axis side of the large-diameter portion, and a horizontal plane and a vertical plane are formed by this notch (see FIG. 2A). Hereinafter, this vertical plane is referred to as the drag generating surface 22. Note that this drag generating surface 22 does not necessarily need to be strictly perpendicular, and for example, an error of about ±10° may be acceptable. Since the plate-like portion is a part for placing the sample S, hereinafter, it is referred to as the sample stage 23. The reason why the sample stage 23 is plate-like is to prevent interference with the lens in the mirror body 12.

[0018] <Cartridge holding portion 3> Next, the details of the cartridge holding portion 3 of this embodiment will be described using FIGS. 3 and 4. Note that FIG. 3 is a side cross-sectional view of the cartridge holding portion 3 with the cartridge 2 inserted, and FIG. 4 is a front view of FIG. 3.

[0019] As shown in FIG. 3, the cartridge holding portion 3 is a substantially circular tubular member fixed to the upper surface of the sample stage 12e, and a through hole 31 having a diameter slightly larger than the outer diameter of the cartridge 2 is formed. In addition, a plurality of cylindrical or spherical rolling elements are provided on the inner surface of the cartridge holding portion 3 so as to contact the cartridge 2 inserted into the through hole 31. Hereinafter, starting from the one on the negative X-axis side, they are referred to as rolling elements 32, 33, and 34. Each rolling element is biased by a rolling element support portion (such as a spring) not shown, and generates a thrust F1 and a drag F2 to be described later by contacting the cartridge 2.

[0020] The rolling elements 32 are primarily used to impart thrust F1 (a force that moves the cartridge 2 in the positive X-axis direction) to the cartridge 2. The thrust generating surface 21 of the cartridge 2, which contacts the rolling elements 32, is a tapered surface with a larger diameter on the positive X-axis side (insertion direction side) and a smaller diameter on the negative X-axis side (anti-insertion direction side). Therefore, the biasing force of the rolling element support (spring, etc.) via the rolling elements 32 acts as a force (thrust F1) that moves the cartridge 2 in the positive X-axis direction. In this embodiment, to suppress uneven distribution of the thrust F1 applied to the thrust generating surface 21, three rolling elements 32 are installed approximately evenly along the outer circumference of the thrust generating surface 21 (for example, at 120° intervals).

[0021] The rolling element 33 is primarily for supporting the cartridge 2 from below and is positioned to contact the negative X-axis end of the large-diameter portion of the cartridge 2. To perform the above function, only one rolling element 33 is installed at a lower position than the other rolling elements. To increase the holding rigidity of the cartridge, multiple rolling elements 33 may be installed in addition to the one at the bottom. However, to avoid excessive restraint, the rolling elements 33 other than the one at the bottom are supported by springs or the like.

[0022] The rolling element 34 is primarily a rolling element that applies a resistance force F2 (a force that moves the cartridge 2 in the negative X-axis direction) to the cartridge 2. The resistance force generating surface 22 of the cartridge 2 that contacts the rolling element 34 is a surface perpendicular to the insertion direction of the cartridge 2 (positive X-axis direction). Therefore, when the cartridge 2 is inserted, the biasing force of the rolling element support part (spring, etc.) via the rolling element 34 acts as a force (resistance force F2) that resists the insertion of the cartridge 2.

[0023] Furthermore, in order to improve the positional accuracy of the sample stage 23 on the YZ plane, in this embodiment, three rolling elements 34 are installed approximately evenly (for example, at 120° intervals) along the outer circumference of the X-axis positive end of the large-diameter portion of the cartridge 2. If the two upper rolling elements 34 were provided with resistance generating surfaces 22 in the same way as the lower rolling elements 34, the cartridge 2 would be excessively constrained. Therefore, in this embodiment, resistance generating surfaces 22 are provided only for the lower rolling elements 34, and the two upper rolling elements 34 are configured to simply contact the outer surface of the cartridge 2. This avoids the influence of manufacturing tolerances when inserting the cartridge 2.

[0024] As described above, the rolling elements 32-34 hold the cartridge 2 inserted into the cartridge holder 3 in a desired position in the X-axis direction by the following mechanism. Specifically, the thrust F1 applied to the thrust generating surface 22 by the rolling elements 32 decreases as the cartridge 2 is inserted, and the drag force F2 applied to the drag generating surface 22 by the rolling elements 34 increases as the cartridge 2 is inserted. Therefore, there exists an insertion amount where the thrust F1 and drag force F2 are balanced. Consequently, the cartridge 2 inserted into the cartridge holder 3 is fixed in the X-axis direction at a predetermined position where the insertion amount balances the thrust F1 and drag force F2.

[0025] On the other hand, when removing the cartridge 2 from the cartridge holder 3, each rolling element rotates, so the resistance force caused by each rolling element is extremely small, and the cartridge 2 can be easily pulled out with little force.

[0026] The above configuration provides a holding structure that balances retention of the insertion direction of cartridge 2 with ease of attachment and detachment. Furthermore, the improved retention reduces sample drift during observation and improves the sample's vibration resistance. Additionally, the improved ease of attachment and detachment results in a structure with less wear debris generated during the attachment and detachment of cartridge 2. [Explanation of Symbols]

[0027] 1…Charged particle beam apparatus, 11…Electron gun, 12…Microscope body, 12a…Irradiation system lens, 12b…Objective lens, 12c…Imaging system lens, 12d…Detector, 12e…Sample stage, 12f…Insertion section, 13…Stand, 14…Main control unit, 15…Stage controller, 2…Cartridge, 21…Thrust generation surface, 22…Drag generation surface, 23…Sample stage, 3…Cartridge holder, 31…Through hole, 32~34…Rolling elements, B…Electron beam, S…Sample

Claims

1. A charged particle generator that irradiates with a charged particle beam, A sample stage into which a cartridge containing the sample is inserted, A group of lenses that focus or amplify the charged particle beam, A detector for detecting the charged particle beam irradiated onto the sample and the charged particles generated from the sample, A charged particle beam apparatus equipped with, The cartridge comprises a substantially cylindrical portion with a notch at the lower part in the non-insertion direction, connected to a plate-shaped portion, and extending from the insertion direction side to the non-insertion direction side, it has a plate-shaped sample holder on which the sample is placed, a drag force generating surface, and a thrust force generating surface. The sample stage has a cartridge holder portion into which the cartridge is mounted, The cartridge holding portion is a substantially cylindrical member with a through hole slightly larger in diameter than the outer diameter of the cartridge, and includes a thrust-applying member that applies thrust to the thrust-generating surface to move the cartridge in the insertion direction, and a resistance-applying member that applies resistance to the resistance-generating surface to move the cartridge in the opposite direction. A charged particle beam apparatus characterized in that at least one of the drag-applying members is a rolling element installed on the inner surface of the cartridge holding portion so as to be in contact with the horizontal and vertical surfaces of the notch.

2. In the charged particle beam apparatus according to claim 1, The thrust generating surface is a tapered surface provided on the side of the cartridge opposite to the insertion direction, with a larger diameter on the insertion direction side and a smaller diameter on the opposite side. The charged particle beam apparatus is characterized in that the drag-generating surface is a substantially vertical surface provided on the side of the cartridge in the insertion direction.

3. In the charged particle beam apparatus according to claim 2, The thrust decreases as the cartridge is inserted. A charged particle beam apparatus characterized in that the aforementioned drag force increases with the insertion of the cartridge.

4. In the charged particle beam apparatus according to claim 3, The cartridge is positioned at a location where the drag and thrust are in equilibrium. A charged particle beam apparatus characterized by being held in the cartridge holding section.

5. In a charged particle beam apparatus according to any one of claims 1 to 4, A charged particle beam apparatus characterized in that a plurality of thrust-applying members are provided along the outer circumference of the cartridge.

6. In a charged particle beam apparatus according to any one of claims 1 to 4, The charged particle beam apparatus is characterized in that a plurality of the drag-applying members are provided along the outer circumference of the cartridge.

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