Ion milling device and ion milling method

Abstract

The present invention provides a processing technology which can suppress the possibility of redeposition on a processing surface and obtain the desired processing content. In order to solve the problem, the ion milling device according to the present invention comprises: an ion source (1) which emits an ion beam; a sample holding part which holds the sample; and a sample sliding movement mechanism (70) which slides the sample holding part in a direction including a normal direction component of the axis of the ion beam.

Description

[0001] This invention patent application is a divisional application of the invention patent application with an international application date of February 26, 2016, a date of entering the Chinese national phase of July 3, 2018, a national application number of 201680077769.0 (international application number PCT / JP2016 / 055868), and an invention name of “Ion Milling Device and Ion Milling Method”. Technical Field

[0002] The present invention relates to an ion milling device and an ion milling method, and more particularly to an ion milling device and an ion milling method for preparing a sample to be observed using, for example, a scanning electron microscope (SEM) or a transmission electron microscope (TEM). Background Art

[0003] An ion milling device is a device for polishing the surface or cross-section of metal, glass, ceramic, etc. by irradiating an argon ion beam or the like, and is suitable as a pre-processing device for observing the surface or cross-section of a sample using an electron microscope.

[0004] In the past, when observing the cross section of a sample using an electron microscope, the area near the desired observation point was cut using, for example, a diamond tool or wire saw. The cut surface was then mechanically ground and mounted on a sample stage for electron microscope observation. Mechanical grinding can cause problems with soft samples, such as polymers or aluminum, such as crushing the observed surface or leaving deep scratches due to abrasive particles. Furthermore, grinding is difficult for hard samples, such as glass or ceramics, and cross-section processing is extremely difficult for composite materials that are a combination of soft and hard materials.

[0005] Ion milling, on the other hand, can process even soft samples without compressing the surface morphology, making it possible to grind strong samples and composite materials. Furthermore, it can easily produce mirror-like cross-sections. For example, Patent Document 1 discloses an ion milling device that reduces the generation of ribbed irregularities on the processed surface by tilting or rotating the sample while irradiating it with an ion beam.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-139938 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] The inventors of the present application have conducted intensive research on a machining method for cross-section milling, and as a result, have obtained the following findings.

[0011] Cross-section milling is a process in which a shield (shield plate) placed above a sample shields a portion of the ion beam and sputters the cross section of the sample along the end face of the shield. As a result, a cross section of the sample along the end face of the shield is obtained.

[0012] However, if processing is required over a processing width (observation width) exceeding the ion beam width or for multiple processing points, the sample chamber must be opened to the atmosphere, the processing position must be changed, the sample chamber must be evacuated again, and then additional processing must be performed. Performing this additional processing reduces throughput.

[0013] The present invention has been made in view of such circumstances, and provides a processing technology capable of preventing a decrease in throughput and obtaining desired processing contents.

[0014] Solutions for solving problems

[0015] In order to solve the above problems, according to the ion milling device of the present invention, an ion beam is irradiated on a sample at least part of which is shielded by a shielding cover to process the sample, and the device comprises: an ion source that emits an ion beam; a sample holding portion that holds the sample; and a sample sliding movement mechanism that causes the sample holding portion to slide along a direction including a normal direction component of the axis of the ion beam.

[0016] Effects of the Invention

[0017] According to the above configuration, it is possible to improve the throughput. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram showing a first configuration example of an ion milling device according to this embodiment.

[0019] Figure 2 1 is a diagram showing a configuration example of the main body of the sample shielding cover unit 21 .

[0020] Figure 3 FIG. 2 is a diagram showing another configuration example of the sample shielding cover unit 21 .

[0021] Figure 4 This is a diagram for explaining a method for making the cross section of a sample parallel to the mask.

[0022] Figure 5 1 is a diagram showing the structure of the sample stage drawing mechanism 60 .

[0023] Figure 6 1 is a diagram showing a configuration example of an optical microscope 40 for observing the shielding positional relationship between the shielding mask 2 and the sample 3 .

[0024] Figure 7 1 and 2 are diagrams showing a state in which the sample shielding cover unit fine movement mechanism 4 provided with the sample shielding cover unit 21 is fixed to the fixing table 42 .

[0025] Figure 8 This is a diagram for explaining a method for aligning a portion of Sample 3 to be cross-section-milled with the center of the ion beam.

[0026] Figure 9 This is a diagram for explaining a method of mirror-polishing the cross section of the sample 3 using an ion beam.

[0027] Figure 10 This is a diagram showing a configuration example 2 of the ion milling device according to the present embodiment, which has a configuration different from that of the configuration example 1 and is capable of realizing both cross-section milling and plane milling.

[0028] Figure 11 The diagram shows a configuration example of a sample shielding cover unit fine movement mechanism 4 provided with a sample shielding cover unit 21. The sample shielding cover unit 21 is mounted on Figure 10 The ion milling apparatus shown.

[0029] Figure 12 This is a diagram for explaining a rotation mechanism provided in the sample unit base 5 for rotating the shield unit fixing portion 52 .

[0030] Figure 13 This is a diagram showing a rotation mechanism that rotates the shield unit fixing portion 52 by rotating the shaft joint 53 .

[0031] Figure 14 This figure shows a state where the sample shielding cover unit fine movement mechanism 4 is installed on the optical microscope 40 in order to adjust the processing position.

[0032] Figure 15 This is a diagram showing an example of the structure of the rotation and tilt mechanism, more specifically showing Figure 12 FIG4 is a diagram showing the structure of a portion A surrounded by a dotted line.

[0033] Figure 16 This is a diagram showing a mechanism for rotating the rotating body 9 using a shaft joint.

[0034] Figure 17 1 is a diagram showing a configuration example of a sliding milling holder (sliding movement mechanism) 70 for slidingly moving the sample shielding cover unit fine movement mechanism 4 in the X-axis direction.

[0035] Figure 18 This is a diagram showing the connection relationship between devices when setting the processing position of ion milling.

[0036] Figure 19This is a flowchart for explaining the procedure of the machining position setting process.

[0037] Figure 20 1 is a diagram showing an example of the arrangement of buttons for setting a destination position in the control box 80 .

[0038] Figure 21 This is a diagram showing a specific example 1 of a method for setting a machining area for wide area milling.

[0039] Figure 22 This is a diagram showing a specific example 2 of a method for setting a machining area for wide area milling.

[0040] Figure 23 This is a diagram showing an example of an operation screen for setting a machining area in wide area milling.

[0041] Figure 24 It is a diagram for explaining the processing process of Sample 3 using wide area milling.

[0042] Figure 25 This is a diagram showing the range of the sliding movement and reciprocating tilting movement when a sliding movement mechanism (sliding milling bracket 70 ) is provided below the rotating body 9 .

[0043] Figure 26 1 and 2 are diagrams showing the rotation and sliding movement of the sample shielding cover unit 21 in the case where a configuration is adopted in which the sliding movement mechanism (sliding milling holder 70 ) is provided below the rotating body 9 .

[0044] Figure 27 This is a diagram showing the range of the sliding movement and reciprocating tilting movement when a sliding movement mechanism (sliding milling bracket 70 ) is provided above the rotating body 9 .

[0045] Figure 28 It is a diagram showing a specific example of a method for setting a machining area for multi-point milling.

[0046] Figure 29 It is a diagram for explaining a machining process 1 of a sample 3 using multi-point milling.

[0047] Figure 30 It is a diagram illustrating a machining process 2 for suppressing the generation of redeposition caused by multi-point milling.

[0048] Figure 31 This figure shows an application example of wide area milling.

[0049] Figure 32 This is a diagram for explaining a method of fixing a plurality of samples having different thicknesses.

[0050] Figure 33This figure shows a state where a plurality of samples having different thicknesses are arranged and fixed on a shielding mask.

[0051] Figure 34 This figure shows a state where samples of different thicknesses are processed and then transferred to an observation device for observation.

[0052] Figure 35 It is a diagram showing the connection relationship between devices when setting the processing position of ion milling according to a modification.

[0053] Figure 36 This is a flowchart for explaining the procedure of the machining position setting process according to the modification. DETAILED DESCRIPTION

[0054] Generally speaking, when processing a width (observation width) greater than the ion beam width or when processing multiple processing points, it is necessary to open the sample chamber to the atmosphere, change the processing position, and then evacuate the sample chamber again before performing additional processing. Performing this additional processing reduces throughput and increases the likelihood of redeposition on the initially processed surface.

[0055] Therefore, embodiments of the present invention are designed to achieve improved throughput while minimizing redeposition caused by ion milling, thereby generating a processed surface of a desired width (wider than the ion beam width) on a sample and / or generating multiple processed points (processed locations) on the sample. This specification discloses at least a mechanism and process for generating a processed surface of a desired width and multiple processed points in a single processing step.

[0056] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this embodiment, an ion milling apparatus equipped with an ion source for irradiating an argon ion beam is described as an example, but the ion beam is not limited to the argon ion beam, and various ion beams can be applied.

[0057] <Structure example of ion milling equipment>

[0058] (i) Device Configuration Example 1

[0059] Figure 1 This is a diagram showing a first configuration example of an ion milling device 100 according to the present embodiment.

[0060] Figure 1The ion milling apparatus 100 includes: a vacuum chamber 15; an ion source 1 mounted on the upper surface of the vacuum chamber; a sample stage 8 located in front of the vacuum chamber 15; a sample unit base 5 extending from the sample stage 8; a sample shield unit fine-motion mechanism 4 mounted above the sample unit base 5; a sample shield unit 21 mounted above the sample shield unit fine-motion mechanism 4; a vacuum exhaust system 6; and a linear guide 11 located in front of the vacuum chamber 15. A sample 3 and a shield 2 are mounted above the sample shield unit.

[0061] The sample shielding cover unit micro-motion mechanism 4 is mounted on the sample unit base 5. The mounting is performed as follows: the lower surface of the sample shielding cover unit micro-motion mechanism 4 (the opposite side of the shielding cover surface that irradiates the ion beam) is brought into contact with the upper surface of the sample unit base 5 and fixed with screws. The sample unit base 5 is configured to be able to rotate and tilt at an arbitrary angle relative to the optical axis of the ion beam, so that the direction of its rotation and tilt and the tilt angle are controlled by the sample stage 8. By rotating and tilting the sample stage 8, the sample 3 arranged on the sample shielding cover unit micro-motion mechanism 4 can be set to a predetermined angle relative to the optical axis of the ion beam. Moreover, the rotation and tilting axis of the sample stage 8 is made to coincide with the position of the upper surface of the sample (the lower surface of the shielding cover), so that a smooth processing surface is effectively produced. In addition, the sample shielding cover unit micro-motion mechanism 4 is configured to be able to move in the vertical direction relative to the optical axis of the ion beam, that is, in the X direction and the Y direction.

[0062] The sample cell base 5 is arranged via a sample stage 8 (rotation mechanism) mounted on a flange 10. The flange 10 also serves as a portion of the container wall of the vacuum chamber 15. When the flange 10 is pulled out along a linear guide 11, and the vacuum chamber 15 is exposed to the atmosphere, the sample cell base 5 is pulled out of the vacuum chamber 15. This constitutes a sample stage pulling mechanism.

[0063] Figure 2 1 is a diagram showing a configuration example of the main body of the sample shielding cover unit 21 . Figure 2 (a) is a top view, and (b) is a side view. In this embodiment, the structure that at least integrally constitutes the sample holder 23 and its rotation mechanism, the shielding cover 2 and its fine adjustment mechanism is referred to as the sample shielding cover unit (main body) 21. Figure 2 The sample holder 23 is rotated by a sample holder rotating ring 22 and a sample holder rotating screw 28. By rotating the sample holder rotating screw 28, the sample holder 23 can be rotated perpendicularly to the optical axis of the ion beam. The sample holder rotating ring 22 is rotated by turning the sample holder rotating screw 28 and is returned by the spring pressure of the reversing spring 29.

[0064] The sample shielding cover unit 21 has a mechanism capable of fine-tuning the position and rotation angle of the shielding cover, and is attached to and detached from the sample shielding cover unit fine-motion mechanism 4. In this embodiment, the sample shielding cover unit 21 and the sample shielding cover unit fine-motion mechanism 4 are composed of two components, but may also be composed of a single component (in this embodiment, the sample shielding cover unit and the sample shielding cover unit fine-motion mechanism are described separately for clarity).

[0065] The shield 2 is secured to the shield bracket 25 using shield fixing screws 27. The shield bracket 25 is moved along the linear guide 24 by operating the shield fine-tuning mechanism (i.e., shield position adjustment unit) 26, thereby fine-tuning the position of the sample 3 and the shield 2. The sample holder 23 is inserted into the sample holder rotating ring 22 from the bottom side and secured. The sample 3 is bonded to the sample holder 23 (for example, using carbon paste, white wax, double-sided tape, etc.). The sample holder position control mechanism 30 adjusts the height position of the sample holder 23 so that the sample holder 23 is in close contact with the shield 2.

[0066] Figure 3 1 is a diagram showing another configuration example of the sample shielding cover unit 21. In this configuration example, a sample holder fixing part 35 is used to suppress the sample holder 23. The other configurations are the same as those in FIG. Figure 2 The structural examples shown are basically the same. Figure 3 (a) shows a state where the sample holder 23 with the sample 3 fixed thereon is installed in the sample shielding cover unit 21. Figure 3 (b) shows a state where the sample holder 23 to which the sample 3 is fixed is detached from the sample shielding cover unit 21 .

[0067] Figure 4 This diagram illustrates how to make the cross section of the sample parallel to the shield. By rotating the sample holder's rotation screw 28 to adjust the position in the X1 direction, fine-tuning is performed under a microscope as follows, so that the cross section of the sample 3 is parallel to the ridgeline of the shield 2. At this point, the shield fine-tuning mechanism 26 is rotated so that the cross section of the sample 3 protrudes slightly from the shield, for example, by approximately 50 μm.

[0068] Figure 5 This diagram shows the structure of the sample stage extraction mechanism 60. The sample stage extraction mechanism 60 consists of a linear guide 11 and a flange 10 fixed thereto. The sample stage is mounted on the flange 10, and the sample unit base 5 fixed to the sample stage is extracted from the vacuum chamber 15 along the linear guide 11. With this operation, the sample shield unit fine-motion mechanism 4, which includes the sample shield unit 21 provided on the sample unit base 5, along with the shield 2, the sample holder 23, and the sample 3, are extracted from the vacuum chamber 15 in an integrated manner.

[0069] In this embodiment, the sample shielding cover unit fine-motion mechanism 4, which includes the sample shielding cover unit 21, is detachably fixed to the sample unit base 5. Therefore, when the sample shielding cover unit fine-motion mechanism 4, which includes the sample shielding cover unit 21, is drawn out of the vacuum chamber 15, the sample shielding cover unit fine-motion mechanism 4, which includes the sample shielding cover unit 21, becomes detachable from the sample unit base 5 (standby for attaching and detaching the sample shielding cover unit 21).

[0070] Figure 5 The figure shows a state in which the sample shielding cover unit fine movement mechanism 4 provided with the sample shielding cover unit 21 is attached and detached from this detachable state. This attachment and detachment can be performed manually or using an appropriate tool.

[0071] Figure 6 1 is a diagram showing a configuration example of an optical microscope 40 for observing the shielding position relationship between the shielding cover 2 and the sample 3. Figure 6 As shown, the optical microscope 40 can be separated from the vacuum chamber 15 and placed in any location. Furthermore, the optical microscope 40 includes the well-known magnifying glass 12 and the magnifying glass fine-motion mechanism 13. Furthermore, the optical microscope 40 includes a fixed table 42 for mounting the sample shielding unit fine-motion mechanism 4, which is provided with the sample shielding unit 21 and is detachable from the observation table 41. Furthermore, the sample shielding unit fine-motion mechanism 4, which is provided with the sample shielding unit 21, is positioned in a reproducible and fixed position using the positioning shaft and holes on the fixed table 42.

[0072] Figure 7 The figure shows a state where the sample shielding cover unit micro-movement mechanism 4 with the sample shielding cover unit 21 is fixed on the fixing table 42. Figure 8 The method described above is to align the part of the sample to be cross-sectioned with the center of the ion beam ( Figure 8 ”+” in the .

[0073] Figure 8This is a diagram for explaining a method for aligning the portion of the sample 3 to be cross-sectioned with the center of the ion beam. Photosensitive paper or copper foil is mounted on the sample holder 23, and the trace formed by irradiating the ion beam, that is, the center of the ion beam and the center of the magnifying glass are aligned by driving X2 and Y2 with the magnifying glass micro-motion mechanism 13. As a result, the center of the ion beam and the center of the optical microscope are in a one-to-one correspondence. In addition, this position adjustment is performed at the time of the cleaning process. The photosensitive paper, copper foil, etc. used for alignment are then removed from the sample holder 23, and the sample shielding cover unit micro-motion mechanism 4 provided with the sample shielding cover unit 21 after the sample 3 is mounted is set on the fixed table 42. By adjusting the position of the sample shielding cover unit micro-motion mechanism 4 in the X3 and Y3 directions to align the portion to be cross-sectioned with the center of the magnifying glass, the center of the ion beam can be aligned with the portion to be cross-sectioned. In this way, when adjusting the shielding position relationship between the shield 2 and the sample 3, the sample shield unit fine-motion mechanism 4 provided with the sample shield unit 21 is removed from the sample unit base 5 and installed on the fixed table 42 of the optical microscope 40, and the shielding position relationship of the shield 2 relative to the sample 3 is adjusted using the shield position adjustment part (shield fine-tuning mechanism).

[0074] Figure 9 This figure illustrates a method for mirror-polishing a cross section of sample 3 using an ion beam. Irradiation with an argon ion beam removes the portion of sample 3 not covered by shield 2 in the depth direction along shield 2, and allows the cross section of sample 3 to be mirror-polished.

[0075] Thus, during ion milling, the sample shielding cover unit fine movement mechanism 4 provided with the sample shielding cover unit 21 including the shielding cover 2 adjusted in its shielding positional relationship with respect to the sample is returned to the sample unit base 5 and mounted.

[0076] As described above, the following ion milling method is constructed. When adjusting the shielding position relationship between the shield 2 and the sample 3, the sample shield unit micro-motion mechanism 4 provided with the sample shield unit 21 is removed from the sample unit base 5 and installed on the fixed table 42 of the optical microscope 40, and the shielding position relationship of the shield relative to the sample 3 is adjusted. During ion milling, the sample shield unit micro-motion mechanism 4 provided with the sample shield unit 21 is returned to the vacuum chamber 15 and installed on the sample unit base 5, wherein the sample shield unit 21 has a shield 2 with an adjusted shielding position relationship relative to the sample.

[0077] (ii) Device Configuration Example 2

[0078] Figure 10 This is a diagram showing a configuration example 2 of the ion milling device 100 according to the present embodiment, which has a configuration different from that of the configuration example 1 and is capable of performing both cross-section milling and plane milling.

[0079] The ion milling apparatus 100 includes: a vacuum chamber 15; a process observation window 7 provided on the upper surface of the vacuum chamber 15; an ion source 1 provided on the left side (or right side) of the vacuum chamber 15; a flange 10 provided on a side different from the side provided with the ion source 1; a sample stage 8 provided on the flange 10; a sample unit base 5 extending from the sample stage 8; a sample shield unit fine-motion mechanism 4 and a sample shield unit 21 mounted on the sample unit base 5; the sample stage 8 provided on the front of the vacuum chamber 15; a shutter 101 provided between the sample and the process observation window 7; and a vacuum exhaust system 6. The sample shield unit 21 includes a shield 2 and carries a sample 3.

[0080] The shutter 101 is provided to prevent the sputtered particles from accumulating on the processing observation window 7. The vacuum chamber 15 is usually constructed in a box-shaped space for forming a vacuum atmosphere, or a shape based on this. The processing observation window 7 is provided above the box (in an environment with gravity, in the direction opposite to the direction of the gravitational field), and the ion source 1 is provided on the side wall of the box (the surface adjacent to the surface above the box, in the direction perpendicular to the direction of the gravitational field). That is, the processing observation window 7 is provided on the wall surface of the vacuum chamber. In addition, in addition to providing a window that can be vacuum-sealed, an optical microscope (including an observation window) and an electron microscope can also be provided in the opening for the processing observation window.

[0081] Figure 11 (a) means that there is a Figure 10 The diagram shows an example of the structure of the sample shielding cover unit 21 of the ion milling device. Figure 2 as well as Figure 3 The structure shown is the same as that shown in FIG. 1 , except that the sample shielding cover unit micro-movement mechanism 4 equipped with the sample shielding cover unit 21 is provided with a shielding cover unit fixing portion 52. In addition, the fixing method of the sample holder 23 is the same as that of FIG. Figure 2 That is, the sample holder 23 is inserted into the key portion 231 of the sample holder 23 from the lower side toward the sample holder rotating ring 22 (a shape that divides the ring into half), and is fixed with screws (see Figure 11 (b) By adopting this fixing method, the processed surface of the sample 3 can be observed from the processing observation window 7.

[0082] Figure 12This is a diagram for explaining a rotating mechanism provided on the sample unit base 5 for rotating the shield unit fixing portion 52. The sample unit base 5 is provided with a rotating body 9 capable of carrying a sample holding component (a component for holding a sample including the sample shield unit micro-motion mechanism 4). The rotating body 9 functions as a support table for supporting the sample holding component. The sample unit base 5 is composed of a rotating body 9, a gear 50, and a bearing 51. The sample shield unit micro-motion mechanism 4 brings the fixing surface (rear face) of the sample shield unit micro-motion mechanism 4 into contact with the upper surface of the rotating body 9 of the sample unit base 5, and is mounted by screwing it from the shield unit fixing portion 52. The sample unit base 5 does not rotate and tilt, but rather can be rotated and tilted at any angle relative to the optical axis of the ion beam irradiated from the side direction of the vacuum chamber 15 using the rotating body 9 mounted on the sample unit base 5, and the direction and angle of rotation and tilt are controlled by the sample stage 8.

[0083] Here, as a method of rotating and tilting the rotating body 9 of the sample unit base 5, there is Figure 12 The method of rotating the sample stage 8 is shown in FIG. Figure 13 Any method of rotating the shaft joint 53 shown can be used. By rotating and tilting the rotating body 9 of the sample unit base 5, the sample 3 placed on the sample shield unit fine motion mechanism 4 can be set to a predetermined angle relative to the optical axis of the ion beam. Furthermore, by aligning the rotation axis of the rotating body 9 of the sample unit base 5 with the position of the sample top surface (the bottom surface of the shield), a smooth, efficiently processed surface can be produced.

[0084] Figure 14 This figure shows the state where the sample shielding cover unit fine movement mechanism 4 is installed on the optical microscope 40 for adjusting the processing position. In addition, it is also possible to install the sample shielding cover unit fine movement mechanism 4 on the optical microscope 40 which is separate from the device, without using the shielding cover unit fixing portion 52, and instead using the lower surface of the sample shielding cover unit fine movement mechanism 4. Figure 14 and Figure 6 The difference is that the magnifying glass micro-motion mechanism 13 for adjusting the ion beam center and the magnifying glass center is carried out on the fixed stage 42 side. The magnifying glass micro-motion mechanism 13 can be used in this example or Figure 6 In addition, Figure 6 Example of the same homework.

[0085] Figure 15 is a diagram showing an example of the structure of the rotation and tilt mechanism, more specifically, Figure 12 FIG. 2 is a diagram showing the structure of the portion A surrounded by a dotted line. Figure 10 ) of ion milling devices, such as Figure 15As shown, the sample rotation tilt mechanism is provided with a rotation function and a tilt mechanism having a rotation tilt axis perpendicular to the ion beam axis. The rotation tilt mechanism utilizes the rotation force of the motor 55 and rotates the rotating body 9 ( Figure 15 By doing so, it is possible to realize an eccentric mechanism in which the ion beam axis is offset from the rotation axis of the sample shielding cover unit micro-motion mechanism 4 when the tilt angle is set to 90 degrees. In addition, as Figure 16 As shown, it is also possible to use a shaft joint. However, when using a shaft joint, it is preferred to Figure 16 As shown, the eccentric mechanism (movement in the Y-axis direction) is provided in the rotating tilting portion, and is provided at the lower portion of the rotating body 9 of the sample unit base 5 .

[0086] like Figure 15 as well as Figure 16 As shown, by giving the ion milling device the function of rotating the sample, the ion beam incident angle and eccentricity can be arbitrarily determined, and cross-sectional milling (milling the sample through a shield to produce a smooth surface) can be performed while plane milling (smoothing the surface perpendicular to the ion beam axis (when the sample table is tilted at an angle of 90 degrees)) can be performed.

[0087] Sliding mechanism for wide-area and multi-point milling

[0088] Below, for Figure 1 as well as Figure 10 (include Figure 12 、 Figure 13 、 Figure 15 、 Figure 16 The present invention will now describe a sliding mechanism for implementing wide-area milling and multi-point milling in an ion milling apparatus 100 having a structure (e.g., any one of the above) . Wide-area milling refers to processing an area on a sample that is wider than the ion beam width. Multi-point milling, on the other hand, refers to processing multiple locations on a sample (particularly, in this embodiment, automatically processing multiple locations).

[0089] The ion milling device 100 capable of performing both wide area milling and multi-point milling needs to be equipped with a sliding mechanism (also referred to as a sliding drive mechanism) capable of moving (sliding) in a vertical direction relative to the optical axis of the ion beam, and slides the sample shielding cover unit 21 in the vacuum chamber. The direction of the sliding movement is preferably parallel to the edge of the shielding cover 2. Moreover, it is preferable that the position of the rotation tilt axis does not move even when the sliding movement is performed (the reason will be referred to later). Figures 25 to 27In order to realize such an ion milling device, the following structure is preferably used. In addition, in this embodiment, the case where the motor serving as the driving source in the X-axis direction is disposed in the vacuum chamber (when the motor is driven) is described, but it may also be disposed outside the chamber.

[0090] In order to perform wide area milling and multi-point milling, in addition to Figure 10 In addition to the structure, it is preferred to perform the X-axis direction (refer to Figure 10 Specifically, by using a motor as the driving source in the X direction of the sample shielding cover unit fine motion mechanism 4, driving in the X direction within the vacuum chamber 15 can be achieved.

[0091] Figure 17 This is a diagram showing a structural example of a sliding milling bracket (sliding movement mechanism) 70 for slidingly moving the sample shielding cover unit micro-motion mechanism 4 in the X-axis direction. In the sliding milling bracket 70, an X-gear 71 is provided on the driving shaft in the X-axis direction of the sample shielding cover unit micro-motion mechanism 4. In addition, a motor unit 72 is provided on the lower surface side of the sample shielding cover unit micro-motion mechanism 4. The motor unit 72 is composed of a motor, an M gear 73, a cover, etc., and the M gear 73 is assembled on the rotating shaft of the motor (it may not be directly installed on the rotating shaft of the motor. It is via the final stage (contacting the X gear 71) gear of the multi-stage gear). The sample shielding cover unit micro-motion mechanism 4 and the motor unit 72 can be either an integrated type or a separated type, and are described here as a separated type. In the separated type, even if the motor unit 72 is removed, general cross-section milling can be performed (based on a manual adjustment method).

[0092] The assembly of the sample shielding cover unit micro-motion mechanism 4 and the motor unit 72 is carried out as follows, using the positioning shaft and hole to maintain a reproducible positional relationship and fix with screws. In this way, the X gear 71 of the sample shielding cover unit micro-motion mechanism 4 contacts the M gear 73 of the motor unit 72. Therefore, if the motor starts to rotate, the X gear 71 rotates via the M gear 73, and the driving shaft in the X-axis direction of the sample shielding cover unit micro-motion mechanism 4 rotates. Therefore, the sample 3 (the sample 3 fixed to the sample shielding cover unit 21) starts to move (slide) in the X-axis direction. By setting it to the above structure, it is possible to realize an ion milling device in which the rotating tilt axis does not move while sliding. In addition, in Figure 10 、 Figure 12 In the ion milling device shown in FIG. 1 , the sliding milling support 70 is arranged on the upper part of the rotating body 9. Figure 1 In the ion milling apparatus shown, a sliding milling support 70 is arranged on the sample unit base 5 .

[0093] <Processing details from setting the processing destination to starting processing>

[0094] Figure 18 This is a diagram showing the connection relationship between devices when setting the processing position of ion milling. Figure 19 This is a flowchart for explaining the process of processing position setting. Figure 18 as well as Figure 19 The following describes an ion milling operation method using a sliding milling holder 70 that combines the sample shielding unit fine motion mechanism 4 and the motor unit 72 provided with the sample shielding unit 21 (operation starting with the sample 3 set on the sample shielding unit 21). The power supply for driving the motor is supplied from the main control unit 103 of the ion milling device 100 via the motor cable (external) 74 and the motor cable (internal) 75.

[0095] Step 1901

[0096] The user (operator) places the sliding milling support 70 on the fixed table 42 of the optical microscope 40 (see Figure 14 ) Connect the motor cable (external) 74 extending from the control unit 103 via the optical microscope side driver 102 to the motor unit of the sliding milling bracket 70.

[0097] (ii) Step 1902

[0098] When step 1901 is completed and the machining position setting process starts, the control unit 103 performs an initialization operation on the sliding milling support 70. Specifically, the sliding milling support 70 mounted on the optical microscope 40 is moved to a reference position (eg, an origin).

[0099] (iii) Step 1903

[0100] After the initialization operation is completed, the user presses an arrow button provided on an operation unit (e.g., a touch panel) 81 or a control box (e.g., separated from the control unit 103 and provided near the optical microscope 40) 80 to move the sliding milling holder 70 carrying the sample 3 to the target position (the position to be processed) (X-axis direction: Figure 8 X3) and press the confirmation button provided on the control box 80 or the like. The movement in the X-axis direction is performed by the motor drive. In addition, adjustments other than the X-axis movement are based on Figure 8 The operation method is the same as described above. If movement in the X-axis direction is performed, the control unit 103 obtains information on the target position (information on the number of pulses corresponding to the number of times the arrow button is pressed to move the sliding milling bracket 70 to the target position). The target position can also be set using a numerical value (e.g., a distance). In this case, for example, the set numerical value (distance) is converted into the number of pulses.

[0101] (iv) Step 1904

[0102] The control unit 103 acquires the information of the destination position acquired in step 1903 (the distance from the origin: the number of pulses generated until the destination position is reached), and stores it in a memory (not shown) within the control unit 103 .

[0103] (v) Step 1905

[0104] When the target position setting using the optical microscope 40 is completed, the user removes the motor cable (external) 74 connected to the sliding milling bracket 70 from the motor unit 72 and removes the sliding milling bracket 70 from the fixed table 42 of the optical microscope 40. The control unit 103 detects that the motor cable (external) 74 has been removed.

[0105] (vi) Step 1906

[0106] Then, the user places the sliding milling holder 70 removed from the optical microscope 40 on the rotating body 9 ( Figure 12 ion milling device structure) or the sample unit base 5 ( Figure 1 Furthermore, the user connects the motor cable (inside) 75 extending from the control unit 103 to the motor unit 72 of the sliding milling holder 70 via the vacuum chamber side driver 104. The control unit 103 detects that the motor unit 72 of the sliding milling holder 70 is connected to the motor cable (inside) 75.

[0107] Then, the user closes the sample stage extraction mechanism 60 and uses the vacuum exhaust system 6 to exhaust the vacuum chamber 15 to create a vacuum state.

[0108] (vii) Step 1907

[0109] The control unit 103 performs an initialization operation of the sliding mill holder 70. Specifically, the control unit 103 moves a reference position (for example, an origin) of the sliding mill holder 70 mounted on the ion milling device.

[0110] The user injects argon gas between the electrodes in the ion source 1, applies a high voltage, and starts discharge. In this state, an acceleration voltage is applied, an ion beam is emitted, and processing begins.

[0111] (viii) Step 1908

[0112] The control unit 103 reads the target position information stored in the memory, controls the vacuum chamber-side driver 104 to drive the motor of the motor unit 72 so as to set the processing position on the sample at the target position.

[0113] In the ion milling device, by rotating the rotating body 9 ( Figure 10 ion milling device), or the sample stage 8 ( Figure 1 The ion milling device of the present invention is configured to tilt back and forth at an arbitrary angle and to perform a sliding reciprocating drive of the sliding milling support 70 (see Figure 24 ), a wide area of ​​the processed surface can be obtained. (The range of the sliding reciprocating drive is between the positions set under the optical microscope 40.) In addition, the sliding reciprocating drive can be either continuous or intermittent. As an example of intermittent drive, one can consider processing for 10 seconds, sliding 0.1 mm → ... → processing for 10 seconds, sliding 0.1 mm, and inputting the stop (processing) time and sliding distance.

[0114] <Processing from Setting the Processing Destination to Starting Processing (Modification)>

[0115] Figure 35 This is a diagram showing a connection relationship between devices when setting a processing position for ion milling according to a modified example. Figure 36 1 is a flowchart for explaining the process of processing position setting according to a modified example. Figure 35 as well as Figure 36 Next, an operation method of ion milling using the sample shielding cover unit fine movement mechanism 4 provided with the sample shielding cover unit 21 (operation starting from a state in which the sample 3 is set in the sample shielding cover unit 21) will be described.

[0116] In the above Figure 18 In the embodiment, the sliding milling support 70 having the motor unit 72 is moved between the vacuum chamber 15 and the optical microscope 40 (using the same motor), while in the modified embodiment, a driving unit (including a motor) is provided on the vacuum chamber 15 side and the optical microscope 40 side, respectively. Therefore, there is no need to move the sliding milling support 70 itself between the vacuum chamber 15 and the optical microscope 40. Thus, in this case, the sample shielding cover unit micro-motion mechanism 4 provided with the sample shielding cover unit 21 can be moved back and forth between the vacuum chamber 15 and the optical microscope 40, and there is no need to insert a cable. Figure 36 During the machining position setting process shown, instead of Figure 19 Step 1901, step 1905, and step 1906, and execute step 3601, step 3602, and step 3603. Figure 19 Different steps 3601 to 3603.

[0117] (i) Step 3601

[0118] The user (operator) mounts the sample shielding cover unit fine movement mechanism 4 on the optical microscope 40 having the drive unit. The motor unit 3502 on the optical microscope 40 side is connected to the motor cable (external) 74 extending from the control unit 103 via the optical microscope side driver 102. Figure 19 Unlike step 1901, there is no need for a motor cable (external) connection process (only the sample shielding cover unit fine-motion mechanism 4 is mounted on the optical microscope 40).

[0119] (ii) Step 3602

[0120] When the target position is set using the optical microscope 40, the user removes the sample shielding cover unit fine movement mechanism 4 from the optical microscope 40 having the drive unit. At this time, the control unit 103 detects that the sample shielding cover unit fine movement mechanism 4 has been removed from the optical microscope 40, and the position alignment in the optical microscope 40 is completed.

[0121] (vi) Step 3603

[0122] Once the alignment of the optical microscope 40 side is completed, the user will install the sample shielding unit fine motion mechanism 4 removed from the optical microscope 40 on the vacuum chamber 15 having the drive unit. The motor unit 3501 on the vacuum chamber 15 side is connected to the motor cable (inside) 75 extending from the control unit 103 via the vacuum chamber side driver 104. Figure 19 Unlike step 1906, the motor cable (inside) connection process is not required (only the sample shielding cover unit fine movement mechanism 4 is mounted on the vacuum chamber 15). At this time, the control unit 103 detects that the sample shielding cover unit fine movement mechanism 4 is mounted on the drive unit of the vacuum chamber 15.

[0123] Then, the user closes the sample stage extraction mechanism 60 and uses the vacuum exhaust system 6 to exhaust the vacuum chamber 15 to create a vacuum state.

[0124] <Specific method for setting the machining area when performing wide area milling>

[0125] Here, a method of setting a machining area when performing wide area milling will be described more specifically. Figure 20 1 is a diagram showing an example of the arrangement of buttons for setting a destination position in the control box 80 . Figure 21 as well as Figure 22 It is a diagram showing a specific example of a method for setting a machining area in wide area milling.

[0126] When performing wide area milling, the user moves the sample 3 (sample shielding unit 21) by using the control box 80 (or the operation panel 80) while looking into the optical microscope 40 (or looking into the microscope at an appropriate time). Figure 20 The left button 76 (left direction), the right button 77 (right direction) in the Figure 21 The two ends E1 and E2 of the area to be processed (processing range 2101) are shown (press Figure 20 78).

[0127] The method of setting the processing area for wide area milling can be as follows Figure 21 As shown, set the two ends of the area you want to process, or you can do Figure 22 As shown, set the center C1 of the area to be processed (processing range 2101). After setting, in the operation unit 81 (or, the control box 80 (in this case, except Figure 20 In addition to the button, the function of inputting the numerical value of the processing area is added) For example, the range of ±2mm from the center can be set to process the set range (sliding reciprocating drive) (refer to Figure 24 ). The machining area for wide area milling is set as follows Figure 23 The user can select either the machining end position or the machining center position on the same operation screen as in the previous example, which improves operability. Whether the machining area is set using the "setting of the end positions" or the "setting of the center position", the machining (milling) action is the same.

[0128] In addition, if Figure 20 As shown, a multi-point milling selection button and a wide area milling selection button are provided on the control box 80, and either or both of them can be selected.

[0129] <Processing process based on wide area milling>

[0130] Figure 24 It is a diagram for explaining the processing process of Sample 3 by wide area milling.

[0131] When performing wide area milling, the absolute position of the ion beam 2401 is fixed, and the sample 3 is made to slide back and forth within the sliding range 2403 by using the sliding movement mechanism (sliding milling support 70) to produce a wide area processing surface 2402 (see Figure 24 (a)).

[0132] Therefore, in the state of irradiating the ion beam 2401, the slide movement mechanism moves the sample 3 from the center to the right end of the processing surface 2402 (see Figure 24 (b)), and slides from the right end to the left end of the processed surface 2402. While the sample 3 moves from the right end to the left end of the processed surface 2402, the ion beam 2401 irradiates the sample 3.

[0133] Next, the sliding mechanism slides the sample 3 from the left end to the right end of the processing surface 2402 (see Figure 24 (c) While the sample 3 is moving from the left end to the right end of the processing surface 2402 , the ion beam 2401 is irradiated onto the sample 3 .

[0134] The above sliding movement is repeated until the processing is completed (refer to Figure 24 (d) and (c)).

[0135] <Reasons for providing a sliding mechanism on the rotating body>

[0136] The above-described device structure is that the rotating body 9 (using Figure 1 In the case of an ion milling device, a sliding mechanism (sliding milling support 70) is provided on the sample stage 8. That is, the reciprocating tilt axis and the processing position of the sample upper surface are always the same. Therefore, even if the sample 3 is tilted back and forth while sliding, interference with the mechanical components within the sample chamber (such as the ion source 1 and ion beam measuring body) is unlikely to occur. Consequently, there are fewer restrictions on the sliding range.

[0137] Figure 25 This is a diagram showing the range of reciprocating tilting motion of a sample during general cross-section milling (a structure not provided with a sliding movement mechanism). Figure 26 This is a diagram showing the range of the sliding movement and reciprocating tilting movement when a sliding movement mechanism (sliding milling bracket 70 ) is provided below the rotating body 9 . Figure 27 This is a diagram showing the range of the sliding movement and reciprocating tilting movement when a sliding movement mechanism (sliding milling bracket 70 ) is provided on the rotating body 9 .

[0138] Generally in the case of cross-section milling ( Figure 25 ), the sample shield unit 21 does not slide, so the position of the rotational tilt axis 2502 (the rotation axis of the rotating body 9) is fixed, and the reciprocating tilting motion 2503 is performed within a fixed range. Therefore, the sample shield unit 21 performing the reciprocating tilting motion 2503 does not interfere with the ion beam measuring body 2501 or the ion source 1.

[0139] On the other hand, Figure 26As shown, in a configuration where the sliding mechanism (sliding milling support 70) is positioned below the rotating body 9, sliding movement of the sample shielding unit 21 also causes the position of the rotational tilting shaft 2502 to slide. Furthermore, in the sample shielding unit 21, the rotational tilting shaft 2502 simultaneously slides (with a constant sliding direction 2601) and performs a reciprocating tilting motion 2503. Consequently, depending on the position of the rotational tilting shaft 2502, the sample shielding unit 21 may interfere with the ion beam measuring body 2501 and the ion source 1 (interference area 2602), potentially preventing a sufficiently wide processing width.

[0140] So, if Figure 27 As shown, a structure is adopted in which a sliding movement mechanism (sliding milling bracket 70) is set on the rotating body 9. In this case, even if the sample shielding cover unit 21 slides, the position of the rotating tilting axis 2502 is fixed. Therefore, although the sliding direction 2701 changes according to the tilt angle of the reciprocating tilting action 2503, the sample shielding cover unit 21 does not interfere with the ion beam measuring body 2501 and the ion source 1 due to the sliding movement and the reciprocating tilting action. Therefore, a larger sliding width can be used during the sliding movement, and a wide processing width can be obtained. In addition, if Figure 26 If multi-point milling is performed on the structure, when processing a position away from the ion beam axis, the position of the rotation tilt axis 2502 changes as described above, so there is also a problem of abnormal milling profile (milling profile becomes left-right asymmetric).

[0141] <Specific method for setting the processing area when performing multi-point milling>

[0142] Here, a method of setting a processing location when performing multi-point milling will be described more specifically. Figure 28 It is a diagram showing a specific example of a method for setting a machining area for multi-point milling.

[0143] In the case of multi-point milling (automatic processing of multiple locations), as in the case of wide area milling, while looking into the optical microscope 40 (or looking into it at the right time), the control box 80 or the operating unit 81 is used to move the sample 3 (sample shielding unit 21) (press the left button 76 (left direction) or the right button 77 (right direction)). More specifically, as Figure 28 As shown (processing position is two positions), set the multiple positions P1 and P2 that you want to process (press the setting button 78). In addition, when performing multi-point milling, it is preferred to fix the edge of the shield 2 in advance in a manner parallel to the direction of sliding movement.

[0144] After the machining position is set, the motor cable (external) 74 is removed from the sliding milling frame 70, and the sliding milling frame 70 is removed from the fixed table 42. Then, the sliding milling frame 70 is mounted on the rotating body 9 or the sample unit base 5, and the motor cable (internal) 75 is connected to the sliding milling frame 70.

[0145] The sample stage extraction mechanism 60 is closed, and the vacuum chamber 15 is evacuated using the vacuum exhaust system 6 to achieve a vacuum state. Furthermore, argon gas is injected between the electrodes in the ion source 1, and a high voltage is applied to initiate discharge. In this state, an accelerating voltage is applied, ion beams are emitted, and processing begins (while simultaneously performing reciprocating tilting).

[0146] <Processing process based on multi-point milling>

[0147] Figure 29 It is a diagram for explaining a machining process 1 of a sample 3 by multi-point milling. Figure 30 This is a diagram for explaining a processing step 2 for suppressing redeposition caused by multi-point milling.

[0148] like Figure 29 As shown in the example (in the case of two processing locations), once processing (processing surface 2902) of processing position 2901 of the first location is completed, the sliding milling bracket 70 is driven (in the X3 direction) to automatically move to processing position 2904 of the second location (sliding drive direction 2903) and begin processing. When selecting a third location or later, the same process is repeated. By employing the above processing method, multi-point milling (automatic processing of multiple locations) is possible.

[0149] However, in the case of processing using this method, Figure 30 As shown in (a), redeposition 3003 may sometimes be generated on the surface of the first processing surface 3001. As a countermeasure, for example, when processing is set to 3 hours at each processing position, processing is performed at the processing position 2901 (first processing surface 3001) of the first part for 1 hour (first time) → moving to the processing position 2904 (second processing surface 3002) of the second part, processing for 1 hour (first time) → moving to the processing position 2901 (first processing surface 3001) of the first part again, processing for 1 hour (second time) → moving to the processing position 2904 (second processing surface 3002) of the second part, processing for 1 hour (second time) → moving to the processing position 2901 (first processing surface 3001) of the first part again, processing for 1 hour (third time) → moving to the processing position 2904 (second processing surface 3002) of the second part, processing for 1 hour (third time), and then the processing is terminated ( Figure 30 (b)). In addition, Figure 30 (c) Figure 30The same applies to (d). With this processing method, the processing time is short, significantly reducing the amount of redeposition on the processed surface. Furthermore, redeposition on the processed surface is removed during the next processing, resulting in a good cross-section. The above processing method is configured by dividing the processing time for a single area into several times or by inputting the divided time.

[0150] In addition, you can also use Figure 30 The processing method shown in (E) is to complete, for example, approximately 95% of the processing (the first time) at the first processing position 2901 (first processing surface 3001), then move to the second processing position 2904 (second processing surface 3002), completing the processing at the second processing position 2904 (second processing surface 3002) in a single operation (e.g., a processing time of 3 hours). Then, the process is moved again to the first processing position 2901 (first processing surface 3001), completing the processing at the first processing position 2901 (first processing surface 3001). This method significantly shortens the processing time at the first processing position 2901 (first processing surface 3001), thereby minimizing the occurrence of redeposition 3003 at the second processing position 2904 (second processing surface 3002).

[0151] Moreover, you can also use Figure 30 (f) The processing method shown is as follows. That is, the processing at the processing position 2901 (first processing surface 3001) of the first part is completed in one time (for example, the processing time is 3 hours), and then the processing is moved to the processing position 2904 (second processing surface 3002) of the second part, and the processing is completed in one time (for example, the processing time is 3 hours). Then, the processing is moved again to the processing position 2901 (first processing surface 3001) of the first part, and the processing position 2901 (first processing surface 3001) of the first part is fine-processed at an acceleration voltage weaker than that during processing. Then, the processing is moved again to the processing position 2904 (second processing surface 3002) of the second part, and the fine-processing is also performed. By finally performing the fine-processing in this way, even if redeposition occurs at the processing position, it can be removed, and the desired processing can be carried out.

[0152] Furthermore, when performing multi-point milling as described above ( Figure 30 (b) to (f)), set each processing position, and set the number of times each processing portion is processed and the processing time in each process.

[0153] If the multi-point milling described above is summarized, multiple processing positions and the number of milling operations at each of the multiple processing positions are set, and each processing position in the sample is processed according to the information of each processing position and the number of milling operations at each processing position. In this case, at least one milling operation is performed alternately at at least a part of the multiple processing positions. That is, for example Figure 30 As shown in (b) to (f), at each processing position, the milling action must be performed alternately once. In addition, at least one processing position among the multiple processing positions, the milling action is performed multiple times at intervals. That is, for example, Figure 30 In (b), after the first milling is performed at the first processing position 3001, the first milling is performed at the second processing position 3002 before the second milling is performed. In addition, the final stage of processing in each processing position is performed in sequence (refer to Figure 30 (b) to (d), and (f)).

[0154] In the existing ion milling device, if the processing of one part is completed, the vacuum chamber needs to be temporarily opened to the atmosphere, and after the processing position is changed, the vacuum chamber needs to be set to a vacuum state again. In contrast, in the ion milling device of this embodiment, multiple parts (for example, three parts) are automatically processed, so the processing of multiple parts can be completed with one treatment. As a result, it is easy to obtain the best processing conditions for the sample to be processed. More specifically, multi-point milling can set respective processing conditions (discharge voltage, acceleration voltage, flow rate, reciprocating tilt angle, cooling temperature, etc.) at each processing position. Therefore, it is easy to approach the optimal conditions. For example, the acceleration voltage of the first part is set to 2kV, the acceleration voltage of the second part is set to 4kV, and the acceleration voltage of the third part is set to 6kV, and a certain sample is processed.

[0155] Furthermore, by enabling wide-area milling to be selected at each processing position in multi-point milling, the system can be applied to a variety of applications.

[0156] Application example of wide area milling

[0157] Figure 31 This figure shows an application example of wide-area milling. Here, a machining method is described for situations where the machining location is not completely clear. This machining method is extremely effective for machining in a short time.

[0158] If it is prior art, then Figure 31 As shown in (a), when the position of the object to be processed (e.g., a defect) is unknown, the processing surface 3102 can only be processed by guesswork using an ion beam 3101. However, this method may take an excessive amount of time.

[0159] Therefore, by applying the wide area milling process, the object to be processed can be found efficiently and processed. Figure 31 As shown in (b), wide area milling is performed (while the sample 3 is tilted and slid back and forth, the ion beam is irradiated). If the object (position) 3103 to be processed is confirmed (optical microscope (set on the upper part of the processing observation window 7) for processing observation, naked eye), the processing is stopped. Then, as Figure 31 As shown in (c), the sample holder is moved (slid) so that the ion beam axis coincides with the position to be processed, and general milling processing is performed.

[0160] This method, which combines wide-area milling suitable for finding a machining position with general milling having a high milling rate, can significantly shorten machining time compared to a case where wide-area milling is performed until the end.

[0161] <Application examples of multi-point milling>

[0162] Figures 32 to 34 This is a diagram for explaining an application example of multi-point milling. Figure 32 This is a diagram for explaining a method of fixing a plurality of samples having different thicknesses. Figure 33 This figure shows a state where a plurality of samples having different thicknesses are arranged and fixed to a shielding mask. Figure 34 The diagram shows a state where samples of different thicknesses are processed, transferred to an observation device, and observed.

[0163] Here, as an application example of multi-point milling, a method for performing cross-sectional milling of multiple samples in a single process will be described. In typical cross-sectional milling, a sample holder 23, to which a sample 3 is bonded, is placed on a sample shielding unit 21. Using this sample securing method, if different samples are bonded to the sample holder 23 and samples of varying thickness are used, a gap will form between the shielding unit 2 and the sample (the thinner one), preventing a smooth cross-section from being obtained.

[0164] So, if Figure 32 (a) to Figure 32As shown in (c), the sample is fixed using a protrusion adjustment jig 90. First, the upper surface (ion beam irradiation side) of the shield 2 is brought into contact with the base 91 of the protrusion adjustment jig 90, and the shield 2 is fixed with the fixing screw 92. When fixing the shield 2, the right wall of the base 91 is used to make the contact surface between the shield 2 and the position adjustment stage 93 parallel. The gap 3201 between the shield 2 and the position adjustment stage 93 (moving along the linear guide) is adjusted using a micrometer 94. When increasing the gap 3201, the micrometer 94 is rotated counterclockwise to form a structure that is pressed by the pressure of the spring 95. After the shield 2 is fixed to the base 91, the micrometer 94 is rotated so that the position adjustment stage 93 contacts the shield 2. The value of the micrometer at this time (initial value) is stored.

[0165] Then, rotate the micrometer 94 counterclockwise to adjust the gap 3201 between the shield 2 and the position adjustment table 93. The distance of the gap 3201 (described later, the protrusion amount and the equal sign) is the value obtained by subtracting the current value of the micrometer 94 from the initial value, so it can be adjusted to any value. After determining the distance of the gap 3201, make the sample 3 as shown in the figure. Figure 32 As shown in (c), while in contact with the position adjustment stage, the fixed position is determined so that the sample 3 is directly bonded to the shield 2 (the surface of the sample 3 on the ion beam irradiation side is in contact with the shield 2). If the sample is bonded in this way, the distance of the gap 3201 becomes the protrusion amount 3301 and the equal sign. Moreover, the sample 3 can be directly fixed to the shield, so multiple samples of different thicknesses can be arranged and fixed. Although not shown in the figure, the protrusion amount 3301 of the sample 3 can be made different (refer to Figure 33 ).

[0166] After all samples are fixed (bonded) to the shield 2, loosen the fixing screws and remove the shield 2 with the samples fixed thereto from the protrusion adjustment fixture. The shield 2 is fixed to the shield support 25 (sample shield unit 21) using the shield fixing screws 27. By adopting the above fixing method and multi-point milling (about the X, Y ( Figure 8 The adjustment of X3 and Y3 (however, X3 is motor driven) has been described above and is therefore omitted), and multiple samples can be milled in one go.

[0167] After processing the plurality of samples fixed to the shield 2, the shield 2 is removed from the ion milling device and mounted on the sample mounting table 105 (see FIG. Figure 34 The sample setting table 105 is configured to be able to fix the shield cover 2 with the fixing screws 106 , so that the shield cover 2 with the sample 3 fixed thereto can be easily fixed to the sample setting table 105 .

[0168] Furthermore, the bottom surface of the sample setting table 105 is provided with an internal thread portion 3401 (in the case where an external thread portion 3402 is provided on the sample fixing table 107 side of the observation device), which can be fixed to the external thread portion 3402 of the sample fixing table 107 of the observation device. This allows the shielding mask 2, with the sample 3 fixed thereto, to be easily placed in the observation device for observation. The internal thread portion 3401 of the sample setting table 105 is preferably positioned so that the processed surface is located on the central axis of the external thread portion 3402, making it easier to find the processed surface during observation.

[0169] Modifications

[0170] (i) in Figure 1 、 Figure 10 In the ion milling device shown, the sample shield unit fine-motion mechanism 4, which carries the sample shield unit 21, can be attached and detached from the sample unit base 5. However, even if the sample unit base 5 and the sample shield unit fine-motion mechanism 4, which carries the sample shield unit 21, are integrated, similar processing can be performed by mounting the optical microscope 40 on the device side. In this case, there is no need to plug in or unplug the motor cable (external) 74, the motor cable (internal) 75, and the sliding milling bracket 70, but the space available for operations such as position adjustment may be limited.

[0171] (ii) In this embodiment, the ion milling device and the observation device (SEM) are described on the premise that they form separate device structures, but these can also be configured as an integrated whole. In this case, for example, the sample unit base 5, the sample shielding cover unit 21, etc. are set to be shared, and a mechanism is set to switch the ion source used during ion milling processing and the electron gun used when observing the processed surface. When ion milling processing is performed, the information (position information) of the processed part is maintained in the control unit 103, so this information can also be used in the observation device, which has the advantage of facilitating control of position alignment during observation. In addition, the trouble of taking out the processed sample from the ion milling device and setting it in the observation device can be saved, so the production volume from processing to observation can be increased.

[0172] Summary

[0173] (i) Wide-area milling: By simultaneously performing reciprocating tilting and sliding motions during ion beam irradiation, a wide processing width is obtained that is independent of the ion beam diameter. Therefore, it is effective for samples that require wide-range observation and analysis. In addition, multi-point milling can slide to a pre-set processing position (which can be multiple) after completing cross-section milling (reciprocating tilting motion during ion beam irradiation), and further cross-section milling is performed at this position. This allows for automatic processing at multiple positions, which can increase production volume.

[0174] The ion milling device of this embodiment has a sample sliding movement mechanism that causes the sample holding portion to slide along the direction of the normal direction component of the axis of the ion beam. In addition, the ion milling device can also have a rotating mechanism that causes the sample holding portion to rotate and tilt around an axis perpendicular to the sliding movement direction of the sample sliding movement mechanism. In this case, it is preferred to configure a sliding movement mechanism (motor drive) on the upper part of the rotating mechanism (a mechanism in which the reciprocating tilting (rotation) axis does not move even when a sliding action is performed), and the position of the rotation axis of the rotating mechanism does not move. In addition, the rotation axis of the rotating mechanism is preferably located on the orbit of the ion beam. Moreover, the sliding movement mechanism preferably causes the sample to slide within a plane perpendicular to the rotation axis of the rotating mechanism. Thus, while the ion beam is being irradiated, not only is the sample subjected to a reciprocating tilting action (general cross-sectional milling), but it can also be subjected to a reciprocating sliding action (sliding action with a width wider than the ion beam width). Using this processing method, the desired processing width (wide area milling) can be obtained with one treatment. The processing width of wide area milling is not limited by the width of the ion beam, so a wide range of processing surfaces (observation surfaces) can be obtained.

[0175] Furthermore, using a sliding mechanism, after completing cross-section milling, the machine automatically moves (slides) to the next processing position, where cross-section milling is repeated. This machining method enables automatic cross-section milling of multiple locations (multi-point milling). Multi-point milling can perform cross-section milling of multiple locations in a single operation, thereby increasing production throughput.

[0176] (ii) The ion milling device of this embodiment includes: an ion source that emits an ion beam; a sample holding portion that holds a sample; a sample sliding mechanism that slides the sample holding portion in a direction that includes a normal component of the ion beam axis; and a control portion. The control portion controls the sample sliding mechanism based on processing information input regarding the processing content of the sample, and is capable of performing wide-area milling to process the sample into a wide area wider than the width of the ion beam, and / or multi-point milling to process multiple locations on the sample. In this manner, wide-area milling and multi-point milling can be automatically performed using a single ion milling device. In addition, wide-area milling and multi-point milling can also be performed in combination.

[0177] (iii) The ion milling apparatus of this embodiment includes a user interface capable of selecting at least one of wide-area milling, which processes a sample into a wide area wider than the width of the ion beam, and multi-point milling, which processes multiple locations on the sample; and a control unit for controlling the milling operation on the sample based on selection input to the user interface. Thus, the user can efficiently execute the desired milling operation by selecting either wide-area milling or multi-point milling, or a combination of the two.

[0178] Furthermore, when both wide area milling and multi-point milling are selected, the control unit controls the milling operation while switching between wide area milling and multi-point milling.

[0179] (iv) In the present embodiment, when ion milling is performed, first, a sample is set in an optical microscope, and the optical microscope is used to set the processing position and processing width of wide-area milling to process a wide area wider than the width of the ion beam in the sample, as well as multiple processing positions of multi-point milling to process multiple parts of the sample. Then, information on the processing position and processing width of wide-area milling, as well as information on multiple processing positions of multi-point milling, are sent to a control unit that controls the milling action. Furthermore, the sample is removed from the optical microscope and set in an ion milling device. Based on the information on the processing position and processing width of wide-area milling, as well as information on multiple processing positions of multi-point milling, the control unit controls the milling action in the ion milling device. Through the above actions, wide-area milling and multi-point milling are performed. In this way, wide-area milling and multi-point milling can be performed automatically and efficiently with a one-time process. In addition, the same process is applied when only wide-area milling or multi-point milling is performed.

[0180] (v) Multi-point milling can also be performed using the following process. First, multiple processing positions when performing multi-point milling and the number of milling operations in the multiple processing positions are set. Then, the above-mentioned multiple processing positions of the sample are processed according to the information of the set multiple processing positions and the set number of milling operations. At this time, at least one milling operation in at least a part of the multiple processing positions is performed alternately, and multiple milling operations are performed at at least one processing position of the multiple processing positions at intervals. When the milling operation is performed at intervals, the milling operation is performed at other processing positions at the intervals. In this way, the redeposition that may occur at each processing position can be made very small.

[0181] In addition, the final stage of processing (final milling operation) of multiple processing positions can also be performed in sequence. By performing the final micro-processing of each processing position in this way, the generation of redeposition at each processing position can be suppressed to a very small extent.

[0182] Furthermore, finish machining can be performed at a plurality of machining positions using an acceleration voltage weaker than the acceleration voltage used when machining is performed alternately. This can also similarly suppress the occurrence of redeposition.

[0183] (vi) According to this embodiment, the following milling process can be performed. First, wide-area milling is performed on the sample to form a wide area wider than the width of the ion beam, and the processing area is searched. Then, the processing area discovered by wide-area milling is milled along the depth direction of the sample. This allows wide-area milling to effectively find difficult-to-find areas, and then to focus on milling these areas. This can improve production throughput.

[0184] (vii) According to the present embodiment, milling processing can also be performed using the following process. First, a plurality of samples are mounted on a sample shield in such a manner that they protrude a predetermined amount from the sample shield. Then, respective processing positions of the plurality of samples are set. Then, an ion beam is irradiated on the sample from the sample shield side, and multi-point milling is performed to process multiple parts of the sample, thereby processing the plurality of samples separately. In this case, the plurality of samples may also include a sample having a thickness different from that of other samples. In this way, samples of different thicknesses can be milled with a single treatment. In addition, the risk of a gap being generated between the sample and the shield due to the different thicknesses of the samples, and the ion beam being able to enter the gap and thereby cause redeposition, can be avoided.

[0185] Description of Reference Numerals

[0186] 1 ion source, 2 shield, 3 sample, 4 sample shield unit micro-motion mechanism, 5 sample unit base, 6 vacuum exhaust system, 7 processing observation window, 8 sample stage, 9 rotating body, 10 flange, 11, 24 linear guide, 12 magnifying glass, 13 magnifying glass micro-motion mechanism, 15 vacuum chamber, 21 sample shield unit, 22 sample holder rotating ring, 23 sample holder, 25 shield holder, 26 shield fine adjustment mechanism, 27 shield fixing screw, 28 sample holder rotating screw, 29 reversal spring, 30 sample holder position control mechanism, 35 sample holder fixing parts, 40 optical microscope, 41 observation platform, 42 fixed platform, 50 gear, 51 bearing, 52 shield unit fixing part, 53 shaft joint, 54 direct-acting device, 55 motor, 60 sample stage extraction mechanism, 70 sliding milling bracket, 71 X gear, 72 motor unit, 73 M gear, 74 motor cable (external), 75 motor cable (internal), 76 left button, 77 right button, 78 setting button, 80 control box, 81 operation unit, 90 protrusion adjustment jig, 91 base, 92 fixing screw, 93 position adjustment table, 94 micrometer, 95 spring, 100 ion milling device, 101 shutter, 102 optical microscope side driver, 103 control unit 104 vacuum chamber side driver, 105 sample setting table, 106 fixing screw, 107 sample fixing table, 2101 processing range, 2401 ion beam, 2402 processing surface, 2403 sliding range, 2501 ion beam measuring body, 2502 rotational tilting axis, 2503 reciprocating tilting action, 2601 sliding direction, 2602 interference part, 2701 sliding direction, 2901 processing position of the first part, 2902 processing surface, 2903 sliding drive direction, 2904 processing position of the second part, 3001 first processing surface 3001, 3002 second processing position, 3003 re-deposition, 3101 ion beam, 3102 processing surface, 3103 object to be processed, 3201 gap, 3301 protrusion amount, 3401 internal thread portion, 3402 external thread portion, 3501 motor unit, 3502 motor unit.

Claims

1. An ion milling device for processing a sample by irradiating an ion beam to a sample at least a portion of which is shielded by a shield, characterized in that: have: an ion source that emits the ion beam; a sample holding portion, which holds the sample; a sample sliding movement mechanism that slides the sample holding portion in a direction including a normal direction component of the axis of the ion beam and is disposed on an upper portion of a rotating mechanism that rotates and tilts the sample holding portion around an axis that is perpendicular to the sliding movement direction of the sample sliding movement mechanism; and Control Department, The control unit controls the sample sliding movement mechanism based on the processing information inputted about the processing content of the sample, and is capable of performing wide area milling for processing the sample into a wide area wider than the width of the ion beam, and / or multi-point milling for processing multiple locations of the sample. The wide area milling is performed by reciprocating sliding motion of the sample sliding movement mechanism while irradiating the ion beam, so that the desired processing width can be obtained in one treatment.

2. An ion milling device for processing a sample by irradiating an ion beam to a sample at least a portion of which is shielded by a shield, characterized in that: have: a user interface capable of selecting at least one of wide area milling for processing the sample into a wide area wider than a width of the ion beam and multi-point milling for processing a plurality of locations of the sample; a sample sliding mechanism that slides the sample holding portion in a direction including a normal direction component of the axis of the ion beam and is disposed on an upper portion of a rotating mechanism that rotates and tilts the sample holding portion around an axis that is perpendicular to the sliding direction of the sample sliding mechanism; and a control unit that controls the milling operation of the sample based on the selection input to the user interface unit, The wide area milling is performed by reciprocating sliding motion of the sample sliding movement mechanism while irradiating the ion beam, so that the desired processing width can be obtained in one treatment.

3. The ion milling device according to claim 2, characterized in that: When both the wide area milling and the multi-point milling are selected by the user interface, the control unit controls the milling operation while switching the operation between the wide area milling and the multi-point milling.

4. An ion milling method for processing a sample by irradiating an ion beam to a sample at least a portion of which is shielded by a shield, characterized in that: The steps include: The sample is placed on an optical microscope, and a processing position and a processing width for wide area milling to process the sample into a wide area wider than the width of the ion beam, and a plurality of processing positions for multi-point milling to process a plurality of locations of the sample are set using the optical microscope; Sending information about the processing position and the processing width of the wide area milling and information about the multiple processing positions of the multi-point milling to a control unit that controls the milling operation; The sample is removed from the optical microscope and placed in an ion milling device, wherein the ion milling device has a sample sliding mechanism that slides a sample holding portion in a direction including a normal direction component of the axis of the ion beam and is placed on an upper portion of a rotating mechanism that rotates and tilts the sample holding portion around an axis that is perpendicular to the sliding direction of the sample sliding mechanism; and The control unit controls the milling action in the ion milling device based on the information of the processing position and the processing width of the wide area milling and the information of the multiple processing positions of the multi-point milling, so as to obtain the required processing width and perform cross-sectional milling of multiple locations in one processing.

5. An ion milling method for processing a sample by irradiating the sample with an ion beam at least a portion of which is shielded by a shield, wherein: The steps include: The sample is placed under an optical microscope, and a processing position and a processing width for wide area milling for processing the sample into a wide area wider than the width of the ion beam are set using the optical microscope; Sending information of the processing position and the processing width of the wide area milling to a control unit that controls the milling action; The sample is removed from the optical microscope and placed in an ion milling device, wherein the ion milling device has a sample sliding mechanism that slides a sample holding portion in a direction including a normal direction component of the axis of the ion beam and is placed on an upper portion of a rotating mechanism that rotates and tilts the sample holding portion around an axis that is perpendicular to the sliding direction of the sample sliding mechanism; and The control unit controls the milling action in the ion milling device based on the information of the processing position and the processing width of the wide area milling, and performs reciprocating sliding action through the sample sliding movement mechanism while the ion beam irradiation is being performed, so as to obtain the desired processing width with one processing.

6. An ion milling method for processing a sample by irradiating an ion beam to a sample at least a portion of which is shielded by a shield, characterized in that: The steps include: The sample is placed on an optical microscope, and a plurality of processing positions for multi-point milling for processing a plurality of locations of the sample are set in the sample using the optical microscope; Sending information of the plurality of processing positions of the multi-point milling to a control unit that controls the milling action; The sample is removed from the optical microscope and placed in an ion milling device, wherein the ion milling device has a sample sliding mechanism that slides a sample holding portion in a direction including a normal direction component of the axis of the ion beam and is placed on an upper portion of a rotating mechanism that rotates and tilts the sample holding portion around an axis that is perpendicular to the sliding direction of the sample sliding mechanism; and The control unit controls the milling operation in the ion milling device based on the information of the plurality of processing positions of the multi-point milling, and performs cross-sectional milling of a plurality of locations in one process.

7. An ion milling method, using an ion milling device, irradiating an ion beam to a sample at least a portion of which is shielded by a shielding cover to process the sample, characterized in that: The steps include: Setting a plurality of processing positions when performing multi-point milling to process a plurality of locations of the sample; Setting the number of milling operations in the plurality of machining positions set above; and According to the information of the plurality of processing positions set above and the number of milling operations set above, the plurality of processing positions of the sample are processed, When the plurality of processing positions are processed by the multi-point milling, at least one milling operation is performed alternately in at least a part of the plurality of processing positions, and a plurality of milling operations are performed at intervals in at least one processing position of the plurality of processing positions, so that cross-section milling of a plurality of parts is performed by one process. The above-mentioned ion milling device has a sample sliding movement mechanism, which enables the sample holding part to slide along the direction including the normal direction component of the axis of the above-mentioned ion beam, and is arranged on the upper part of the rotating mechanism. The above-mentioned rotating mechanism enables the above-mentioned sample holding part to rotate and tilt around an axis perpendicular to the sliding movement direction of the above-mentioned sample sliding movement mechanism.

8. The ion milling method according to claim 7, characterized in that: During the milling operation at the at least one machining position in which the milling operation is performed a plurality of times at intervals of the time, the milling operation at the other machining positions is performed.

9. The ion milling method according to claim 7, characterized in that: The final stage of processing is performed sequentially in the above-mentioned plurality of processing positions.

10. The ion milling method according to claim 7, characterized in that: The method further includes the step of performing finish machining at the plurality of machining positions using an acceleration voltage weaker than the acceleration voltage used during the alternating machining.

11. An ion milling method, using an ion milling device, irradiating an ion beam to a sample at least a portion of which is shielded by a shielding cover to process the sample, characterized in that: The steps include: For the sample, performing a reciprocating sliding motion while the ion beam is being irradiated, thereby performing wide area milling to process a wide area wider than the width of the ion beam, and searching for a processing portion; and The processing portion found by the wide area milling is milled along the depth direction of the sample to obtain the required processing width with one treatment. The above-mentioned ion milling device has a sample sliding movement mechanism, which enables the sample holding part to slide along the direction including the normal direction component of the axis of the above-mentioned ion beam, and is arranged on the upper part of the rotating mechanism. The above-mentioned rotating mechanism enables the above-mentioned sample holding part to rotate and tilt around an axis perpendicular to the sliding movement direction of the above-mentioned sample sliding movement mechanism.

12. An ion milling method, using an ion milling device, irradiating an ion beam to a sample at least a portion of which is shielded by a shielding cover to process the sample, characterized in that: The steps include: A plurality of samples are mounted on the sample shield so as to protrude from the sample shield by a predetermined amount; setting processing positions for each of the plurality of samples; and irradiating the sample with the ion beam from the sample shielding cover side, performing multi-point milling to process multiple locations of the sample, and processing the multiple samples respectively; Perform cross-section milling of multiple locations in one process. The above-mentioned ion milling device has a sample sliding movement mechanism, which enables the sample holding part to slide along the direction including the normal direction component of the axis of the above-mentioned ion beam, and is arranged on the upper part of the rotating mechanism. The above-mentioned rotating mechanism enables the above-mentioned sample holding part to rotate and tilt around an axis perpendicular to the sliding movement direction of the above-mentioned sample sliding movement mechanism.

13. The ion milling method according to claim 12, characterized in that: The plurality of samples include a sample having a thickness different from that of other samples.

14. An ion milling device for processing a sample by irradiating an ion beam to a sample at least a portion of which is shielded by a shield, wherein: have: an ion source that emits the ion beam; a sample holding portion, which holds the sample; a sample sliding movement mechanism that slides the sample holding portion in a direction including a normal direction component of the axis of the ion beam and is disposed on an upper portion of a rotating mechanism that rotates and tilts the sample holding portion around an axis that is perpendicular to the sliding movement direction of the sample sliding movement mechanism; and Control Department, The control unit controls the sample sliding movement mechanism based on the processing information inputted about the processing content of the sample, and can perform multi-point milling for processing multiple locations of the sample, thereby performing cross-sectional milling of multiple locations in one process.

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