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

charged particle beam equipment

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

[0002] Patent Document 1 is known as a document related to a sample cartridge for a charged particle beam device. For example, paragraph 0016 of Patent Document 1 states, "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 on which the cartridge 150 is mounted. The mounting portion 112 has a leaf spring 116, and the cartridge 150 mounted on the mounting surface 114 is pressed against the block 120 and the block 122 by the leaf spring 116. This fixes the cartridge 150."

[0003] Furthermore, paragraph 0017 of the same document states, "Blocks 120 and 122 are components that come into contact with cartridge 150 when cartridge 150 is placed on mounting surface 114. Blocks 120 and 122 function as guides to guide cartridge 150 when cartridge 150 is attached to mounting portion 112."

[0004] As described above, the sample holder of Patent Document 1 has a surface on which the cartridge is placed and two blocks that are pressed by springs and act as guides, and these blocks hold the cartridge.

[0005] Japanese Patent Application Laid-Open No. 2022-107299

[0006] However, in the sample holder of Patent Document 1, the cartridge is held only by the frictional force with the contact surface, so if the rigidity of the leaf spring is increased to increase the frictional force in order to improve the holding force, the increased holding force of the cartridge comes at the expense of making it difficult to attach and detach the cartridge.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a charged particle beam device that achieves both a strong holding force and ease of attachment and detachment of a cartridge.

[0008] In order to solve the above-mentioned problems, one representative charged particle beam device of the present invention is a charged particle beam device comprising: a charged particle generator that irradiates a charged particle beam; a sample stage into which a cartridge carrying a sample is inserted; a group of lenses that converge or expand the charged particle beam; and a detector that detects the charged particle beam irradiated onto the sample and the charged particles generated from the sample, wherein the cartridge has, from the insertion direction side toward the counter-insertion direction, a sample stage on which the sample is placed, a drag generating surface, and a thrust generating surface, the sample stage has a cartridge holding part to which the cartridge is attached, and the cartridge holding part has a thrust applying member that applies a thrust to the thrust generating surface to move the cartridge in the insertion direction, and a drag applying member that applies a drag to the drag generating surface to move the cartridge in the counter-insertion direction.

[0009] According to the charged particle beam device of the present invention, it is possible to achieve both a holding force and detachability of the cartridge.

[0010] FIG. 1 is a schematic side view showing the entire configuration of a charged particle beam device according to an embodiment; FIG. 2 is a side view of a cartridge according to an embodiment; FIG. 3 is a top view of a cartridge according to an embodiment; FIG. 4 is a front view of a cartridge according to an embodiment; FIG. 5 is a rear view of a cartridge according to an embodiment; FIG. 6 is a side view of a cartridge holding part into which the cartridges of FIGS. 2A to 2D are inserted; and FIG. 7 is a front view of a cartridge holding part into which the cartridges of FIGS. 2A to 2D are inserted.

[0011] An embodiment of the charged particle beam device of the present invention will be described below using a transmission electron microscope that images a sample placed in a cartridge as an example.

[0012] <Charged Particle Beam Device 1> FIG. 1 is a schematic side view showing the entire configuration of a charged particle beam device 1 (transmission electron microscope) according to one embodiment of the present invention. As shown in the figure, the charged particle beam device 1 includes, from top to bottom, an electron gun 11 that irradiates an accelerated electron beam B, a microscope body 12, and a mount 13 that supports the electron gun 11 and the microscope body 12. It also includes a main control unit 14 and a stage controller 15 that control the charged particle beam device 1. Specifically, the main control unit 14 and the stage controller 15 are computers that include hardware such as a calculation device (e.g., a CPU), a main storage device (e.g., a semiconductor memory), an auxiliary storage device (e.g., a hard disk), and a communication device. The calculation 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. However, the following description will omit such well-known techniques as appropriate.

[0013] 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 a cartridge 2 into the sample stage 12e, the insertion section 12f can be closed to vacuum-seal the sample stage 12e. A cartridge holder 3 for mounting the cartridge 2 is also provided inside the sample stage 12e.

[0014] In the following description, the insertion direction of the 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, the sample stage 12e is equipped with a drive mechanism for moving the position of the cartridge 2 in the X-, Y-, and Z-axis directions and for changing the orientation of the cartridge 2 around the X-, Y-, and Z-axes. By controlling the drive mechanism in accordance with commands from the stage controller 15, the sample S on the cartridge 2 inserted in the sample stage 12e can be set to a desired position and orientation.

[0015] To obtain an observation image of the sample S placed in the cartridge 2, the charged particle beam device 1 of this embodiment operates as follows. First, using an automatic loading device or the like, the cartridge 2 containing the sample S is inserted from the insertion section 12f onto 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. Thereafter, under the control of the main control unit 14, the electron gun 11 irradiates the electron beam B toward the mirror body 12. Inside the mirror body 12, the electron beam B is converged by the illumination system lens 12a and the objective lens 12b and irradiates the sample S on the 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. An electrical signal from the detector 12d is then input to the main control unit 14, thereby forming an image of the sample S.

[0016] <Cartridge 2> Next, the shape of the cartridge 2 of this embodiment will be described with reference to Figures 2A to 2D. Figure 2A is a side view of the cartridge 2, Figure 2B is a top view of the cartridge 2, Figure 2C is a front view of the cartridge 2, and Figure 2D is a rear view of the cartridge 2.

[0017] As shown in these figures, the cartridge 2 comprises a generally cylindrical portion on the negative X-axis side (opposite the insertion direction) and a plate-like portion on the positive X-axis side (the insertion direction). The generally 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 will be referred to as the thrust generating surface 21. A notch is provided at the bottom of the large-diameter portion on the positive X-axis side, forming a horizontal plane and a vertical plane (see FIG. 2A ). Hereinafter, this vertical surface will be referred to as the drag generating surface 22. Note that the drag generating surface 22 does not need to be strictly vertical; for example, an error of approximately ±10° is acceptable. Because the plate-like portion is used to place the sample S, it will be referred to as the sample stage 23. The sample stage 23 is plate-like to prevent interference with the lenses in the microscope body 12.

[0018] <Cartridge holding portion 3> Next, the cartridge holding portion 3 of this embodiment will be described in detail with reference to Figures 3 and 4. Figure 3 is a side cross-sectional view of the cartridge holding portion 3 with the cartridge 2 inserted, and Figure 4 is a front view of Figure 3.

[0019] 3, the cartridge holding portion 3 is a substantially cylindrical member fixed to the upper surface of the sample stage 12e, and has a through-hole 31 formed therein that is slightly larger in diameter than the outer diameter of the cartridge 2. The inner surface of the cartridge holding portion 3 is provided with a plurality of cylindrical or spherical rolling elements that come into contact with the cartridge 2 inserted into the through-hole 31. Hereinafter, these rolling elements will be referred to as rolling elements 32, 33, and 34, in order from the X-axis negative side. Each rolling element is biased by a rolling element support portion (such as a spring) not shown, and generates a thrust force F1 and a drag force F2, which will be described later, by coming into contact with the cartridge 2.

[0020] The rolling elements 32 are primarily used to apply a thrust F1 (a force that moves the cartridge 2 in the positive direction of the X-axis) to the cartridge 2. The thrust generating surface 21 of the cartridge 2, which comes into contact with the rolling elements 32, is a tapered surface with a larger diameter on the positive X-axis side (the insertion direction side) and a smaller diameter on the negative X-axis side (the side opposite to the insertion direction), so that the biasing force of the rolling element support portion (such as a spring) that passes through the rolling elements 32 acts as a force (thrust F1) that moves the cartridge 2 in the positive X-axis direction. In order to prevent the thrust F1 applied to the thrust generating surface 21 from being biased to one side, in this embodiment, three rolling elements 32 are disposed approximately evenly (e.g., at 120° intervals) along the outer periphery of the thrust generating surface 21.

[0021] The rolling element 33 is primarily a rolling element for supporting the cartridge 2 from below, and is provided at a position where it comes into contact with the end of the large-diameter portion of the cartridge 2 in the negative X-axis direction. To perform the above function, only one rolling element 33 is provided, at a position lower than the other rolling elements. To increase the cartridge holding rigidity, multiple rolling elements 33 may be provided, not just at the bottom. However, to avoid excessive constraint, the rolling elements 33 other than those at the bottom are supported by springs or the like.

[0022] The rolling element 34 is a rolling element that mainly applies a resistance force F2 (a force that moves the cartridge 2 in the negative direction of the X-axis) to the cartridge 2. The resistance force generating surface 22 of the cartridge 2 that comes into contact with the rolling element 34 is a surface that is perpendicular to the insertion direction of the cartridge 2 (positive direction of the X-axis), so when the cartridge 2 is inserted, the biasing force of the rolling element support portion (spring or the like) that passes through the rolling element 34 acts as a force (resistance force F2) that resists the insertion of the cartridge 2.

[0023] In order to improve the positional accuracy of the sample stage 23 on the YZ plane, in this embodiment, three rolling elements 34 are disposed approximately evenly (e.g., at 120° intervals) along the outer periphery of the end of the large-diameter portion of the cartridge 2 in the positive direction of the X axis. If the two upper rolling elements 34 were provided with a resistance generating surface 22 like the lower rolling elements 34, this would result in excessive constraint on the cartridge 2. Therefore, in this embodiment, the resistance generating surface 22 is provided only on the lower rolling element 34, and the two upper rolling elements 34 are configured so that they only come into contact with the outer periphery of the cartridge 2. This makes it possible to avoid the effects of manufacturing tolerances when inserting the cartridge 2.

[0024] The above-described rolling elements 32 to 34 hold the cartridge 2 being inserted into the cartridge holding portion 3 at a desired position in the X-axis direction by the following mechanism. That is, the thrust F1 applied to the thrust generating surface 22 by the rolling element 32 gradually decreases as the cartridge 2 is inserted, and the drag F2 applied to the drag generating surface 22 by the rolling element 34 gradually increases as the cartridge 2 is inserted, so there is an insertion amount at which the thrust F1 and the drag F2 are balanced. Therefore, the cartridge 2 inserted into the cartridge holding portion 3 is fixed in the X-axis direction at a predetermined position at which the insertion amount is such that the thrust F1 and the drag F2 are balanced.

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

[0026] The above configuration provides a holding structure that is both easy to hold and easy to attach / detach in the insertion direction of the cartridge 2. The increased holding ability also improves the resistance to sample drift and vibration that occurs during observation. The increased detachability also results in a structure that generates less wear powder when the cartridge 2 is attached or detached.

[0027] 1...Charged particle beam device, 11...Electron gun, 12...Mirror body, 12a...Illumination system lens, 12b...Objective lens, 12c...Imaging system lens, 12d...Detector, 12e...Sample stage, 12f...Insertion part, 13...Stand, 14...Main control unit, 15...Stage controller, 2...Cartridge, 21...Thrust generating surface, 22...Drag generating surface, 23...Sample stage, 3...Cartridge holding part, 31...Thrust hole, 32-34...Rolling body, B...Electron beam, S...Sample

Claims

1. A charged particle generation 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 converges or diverges the charged particle beam, A detector that detects the charged particle beam irradiated on the sample and charged particles generated from the sample, A charged particle beam apparatus comprising: The cartridge is a substantially cylindrical portion provided with a notch at the lower part in the reverse insertion direction and is connected to a plate-like portion, and includes a plate-like sample stage on which the sample is placed, a resistance generating surface, and a thrust generating surface, from the insertion direction side toward the reverse insertion direction side. The sample stage has a cartridge holding portion on which the cartridge is mounted. The cartridge holding portion is a substantially circular tubular member having a through hole slightly larger in diameter than the outer diameter of the cartridge, and includes a thrust applying member that applies a thrust for moving the cartridge in the insertion direction to the thrust generating surface, and a resistance applying member that applies a resistance for moving the cartridge in the reverse insertion direction to the resistance generating surface. A charged particle beam apparatus, wherein at least one of the resistance applying members is a rolling body installed on the inner surface of the cartridge holding portion so as to contact 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 reverse insertion direction side of the cartridge, with the insertion direction side having a larger diameter and the reverse insertion direction side having a smaller diameter. A charged particle beam apparatus, wherein the resistance generating surface is a substantially vertical surface provided on the insertion direction side of the cartridge.

3. In the charged particle beam apparatus according to Claim 2, The thrust decreases as the cartridge is inserted. A charged particle beam apparatus, wherein the resistance increases as the cartridge is inserted.

4. In the charged particle beam apparatus according to Claim 3, The cartridge is held by the cartridge holding portion at a position where the resistance and the thrust are balanced. A charged particle beam apparatus, characterized in that.

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

6. In the charged particle beam apparatus according to any one of Claims 1 to 4, A charged particle beam apparatus, characterized in that a plurality of the resistance applying members are provided along the outer periphery of the cartridge.