Ion beam tiltable sample table and processing and testing combined method

Abstract

The invention discloses an ion beam tiltable sample table which comprises a support, a connecting seat connected with the support, a sample support connected with the connecting seat, a reed arranged on the sample support and a pressing piece arranged on the reed, the pressing piece, the reed and the sample support are connected and fixed, the sample support and the connecting seat are connected and fixed through a middle shaft and a middle shaft nut, and the middle shaft nut is connected with the connecting seat. The middle shaft penetrates through the sample support and the connecting seat and is fixed through a middle shaft nut; and the support is rotatably mounted on an FIB sample table. The device has the beneficial effects that in the aspects of FIB fixed-point and fixed-orientation processing of a sample and FIB and TKD analysis combination, multiple sample processing modes are realized, sample clamping is facilitated, and damage to the sample is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of focused ion beam processing, in particular to an ion beam tiltable sample stage and a processing and testing combined method. Background Art

[0002] At present, focused ion beam (FIB) processing technology has been widely used. Its main feature is that it can point and hit anywhere. Specifically, it can observe the structure and position the processing with a processing accuracy of ±2nm. With the progress of material science, the requirements for fixed-point processing are getting higher and higher. Not only the processing sampling position must be clear, but also the samples with fixed orientation must be extracted. This is difficult to achieve with current technology. A large number of electron backscatter diffraction (EBSD) tests are required to find grains with suitable orientations and then extract samples. This method requires luck on the one hand, and on the other hand, the amount of data in the early stage is large, which requires manual search, and the workload is large and difficult.

[0003] In addition, the transmission electron Kikuchi diffraction analysis (TKD) in the scanning electron microscope (SEM) is aimed at ultra-thin crystal samples. It uses the interaction between the electron beam and the sample to generate transmission electron Kikuchi diffraction. By collecting these signals, it is possible to analyze crystallographic related information, and can achieve high-resolution crystallographic related information. It has a wide range of applications in material research, semiconductor testing, failure analysis, etc. For welding, semiconductor and other samples, it is necessary to use a focused ion beam (FIB) to extract the sample at a fixed point for analysis; because FIB and TKD have different requirements for sample placement, the previous method requires first processing the sample with FIB under vacuum, then breaking the vacuum and exiting the chamber, replacing the sample stage or adjusting the sample angle, and then vacuuming for TKD analysis. On the one hand, the traditional method requires repeated exiting the chamber, which is inefficient; on the other hand, because the vacuum needs to be broken, it is extremely unfriendly to some samples that are easily oxidized;

[0004] In view of the above situation, it is necessary to improve the existing focused ion beam sample extraction method so that it can adapt to the current needs of sample processing. Summary of the invention

[0005] To achieve the above-mentioned purpose, the technical solution of the present invention is an ion beam tiltable sample stage, comprising a support, a connecting seat connected to the support, a sample holder connected to the connecting seat, a spring arranged on the sample holder, and a pressure plate arranged on the spring, wherein the pressure plate, the spring and the sample holder are connected and fixed, the sample holder and the connecting seat are connected and fixed by a central axis and a central axis nut, the central axis passes through the sample holder, and the connecting seat is fixed by the central axis nut; the support can be rotatably mounted on the FIB sample stage.

[0006] As a further supplement to the technical solution, threaded holes are provided on the connecting seat and the support, and a first fixing screw is installed in the threaded hole to connect and fix the connecting seat and the support.

[0007] As a further supplement to the technical solution, the pressing plate, the reed plate and the sample holder are connected and fixed by a second fixing screw and a fixing nut, and the second fixing screw passes through the pressing plate, the reed plate and the sample holder in sequence and is fixed by the fixing nut.

[0008] As a further supplement to the technical solution, two sets of second fixing screws and fixing nuts are provided on the pressing plate, the spring plate and the sample holder.

[0009] As a further supplement to the technical solution, gaskets are provided on both sides of the central axis on the sample holder.

[0010] As a further supplement to the technical solution, there are at least four gaskets and at least one on each side.

[0011] A processing and testing method for an ion beam tiltable sample stage comprises the following steps:

[0012] Step 1: Perform EBSD test on the sample surface to clarify the spatial orientation of the target grain in the sample. The EBSD result can show the angle between the grain and the XYZ axis of the macro sample position;

[0013] Step 2: break the vacuum, open the sample chamber, and rotate the angle between the sample holder and the vertical axis to the desired angle;

[0014] Step 3: Close the sample chamber and evacuate it. After the vacuum is established, turn on the electron beam to find the sample position and process it using the conventional FIB processing TEM sample method.

[0015] Step 4: Break the vacuum, open the sample chamber, and rotate the sample holder to the desired angle with the vertical;

[0016] Step 5: Close the sample chamber and evacuate the chamber. After the chamber is evacuated, turn on the electron beam to find the sample position, extend the EBSD probe into the designated position, and perform the EBSD test of the transmission beam.

[0017] Its beneficial effect is that it can realize a variety of sample processing methods in FIB fixed-point and fixed-orientation processing, as well as the combination of FIB and TKD analysis, facilitate sample clamping, and avoid damage to the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of the processing and testing combined method of the present invention from a first angle;

[0019] Figure 2 It is a second angle structural schematic diagram of the processing and testing combined method of the present invention;

[0020] Figure 3 It is a schematic diagram of the structure of the sample stage of the present invention;

[0021] In the figure, 1. support; 2. connecting seat; 3. sample holder; 4. spring; 5. pressing plate; 6. central axis; 7. central axis nut; 8. first fixing screw; 9. second fixing screw; 10. fixing nut; 11. EBSD probe; 12. tungsten needle; 13. FIB sample stage; 14. sample. DETAILED DESCRIPTION

[0022] In order to make the technical solution more clear to those skilled in the art, Figure 1 -3 Detailed description of the technical solution of the present invention:

[0023] An ion beam tiltable sample stage comprises a support 1, a connecting seat 2 connected to the support 1, a sample holder 3 connected to the connecting seat 2, a spring 4 arranged on the sample holder 3, and a pressing plate 5 arranged on the spring 4, wherein the pressing plate 5, the spring 4, and the sample holder 3 are connected and fixed, and the sample holder 3 is connected and fixed to the connecting seat 2 via a central axis 6 and a central axis 6 nut, and the central axis 6 passes through the sample holder 3, and the connecting seat 2 is fixed via the central axis 6 nut; the support 1 is rotatably mounted on a FIB sample stage 13; wherein the pressing plate 5 and the spring 4 are used to clamp the sample, and wherein the FIB sample stage 13 is used to place a sample 14, on which the final sample to be tested is extracted and moved to the sample holder 3.

[0024] The connecting seat 2 and the support 1 are provided with threaded holes, and the first fixing screws 8 are installed in the threaded holes to connect and fix the connecting seat 2 and the support 1.

[0025] Among them, the pressing plate 5, the reed 4, and the sample holder 3 are connected and fixed by the second fixing screw 9 and the fixing nut 10. The second fixing screw 9 passes through the pressing plate 5, the reed 4, and the sample holder 3 in sequence and is fixed by the fixing nut 10. Furthermore, two sets of second fixing screws 9 and fixing nuts 10 are provided on the pressing plate 5, the reed 4, and the sample holder 3.

[0026] Among them, gaskets are provided on both sides of the sample holder 3 on the central axis 6. Preferably, there are at least four gaskets and at least one on each side. During installation, a torque wrench is required to set the torque value and tighten the nut of the central axis 6. Through appropriate torque, the sample holder 3 can be fixed at any angle under the friction between the gaskets.

[0027] A processing and testing method for an ion beam tiltable sample stage comprises the following steps:

[0028] Step 1: Perform EBSD test on the sample surface to determine the spatial orientation of the target grains in the sample, and adjust the angle of the sample by manually rotating the sample holder 3; Figure 1As shown in Figure 2, the EBSD result can show the angle between the grain and the XYZ axis of the macro sample position; the angle of the X axis can be reset by rotating the FIB sample stage 13, and the angle of the Z axis can be reset by tilting our sample holder, so that the sample can be extracted with a determined orientation; Example: The angle between the sample and the X axis is 12°, and the angle with the Z axis is 23°;

[0029] Step 2: break the vacuum, open the sample chamber, and rotate the sample holder 3 to a desired angle with the vertical axis; in the present invention, the angle between the sample to be taken and the vertical axis is 23°;

[0030] Step 3: Close the sample chamber and evacuate. After the vacuum is completed, rotate the sample stage 12° so that the angle between the area to be taken and the X-axis is 0°. Turn on the electron beam to find the sample position and use the conventional FIB processing TEM sample method for processing. The main steps are as follows:

[0031] Step 1: FIB finds the grains to be taken in the sample and processes the sample in FIB;

[0032] Step 2: The tungsten needle 12 extracts the sample;

[0033] Step 3: Control the angle between the sample holder 3 and the vertical axis to be 23°;

[0034] Step 4: Transfer the sample to a copper mesh stand that has been tilted to a suitable angle;

[0035] Step 5: Cut off the tungsten needle 12 and thin the sample. It should be noted that: because the sample has been tilted 23°, and the conventional ion thinning takes 52° as the neutral plane, the sample stage only needs to be tilted 52-23=29° as a whole to be the neutral plane, and the rest of the thinning procedures are the same as the conventional procedures;

[0036] Step 6: After thinning, turn off the electron beam and ion beam, break the vacuum, open the chamber, rotate the sample holder 3 to an angle of 20° with the horizontal, close the sample chamber, evacuate the vacuum, turn on the electron beam, find the thinned sample, and enter the EBSD probe 11 for t-EBSD testing.

[0037] Step 4: break the vacuum, open the sample chamber, and rotate the sample holder (3) to a desired angle with the vertical, which is 70° in the present invention;

[0038] Step 5: Close the sample chamber and evacuate the chamber. After the chamber is evacuated, turn on the electron beam to find the sample position, extend the EBSD probe into the designated position, and perform the EBSD test of the transmission beam.

[0039] The above is the whole experimental process. It can realize sample extraction at any angle and perform t-EBSD analysis. At the same time, the device is also compatible with coaxial t-EBSD. The detection surface of coaxial t-EBSD is parallel to the horizontal direction and is located below the sample. When using coaxial t-EBSD, rotate the sample holder 3 to a horizontal position and then perform coaxial t-EBSD testing.

[0040] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Some changes that may be made to certain parts thereof by technicians in this technical field all reflect the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. An ion beam tiltable sample stage, characterized in that: The invention comprises a support (1), a connecting seat (2) connected to the support (1), a sample holder (3) connected to the connecting seat (2), a spring (4) arranged on the sample holder (3), and a pressing plate (5) arranged on the spring (4); the pressing plate (5), the spring (4), and the sample holder (3) are connected and fixed; the sample holder (3) and the connecting seat (2) are connected and fixed via a central axis (6) and a central axis (6) nut; the central axis (6) passes through the sample holder (3), and the connecting seat (2) is fixed via the central axis (6) nut; the support (1) is rotatably mounted on a FIB sample stage (13).

2. The ion beam tiltable sample stage according to claim 1, characterized in that: The connecting seat (2) and the support seat (1) are provided with threaded holes, and a first fixing screw (8) is installed in the threaded hole to connect and fix the connecting seat (2) and the support seat (1).

3. The ion beam tiltable sample stage according to claim 2, characterized in that: The pressing plate (5), the reed plate (4), and the sample holder (3) are connected and fixed by a second fixing screw (9) and a fixing nut (10); the second fixing screw (9) passes through the pressing plate (5), the reed plate (4), and the sample holder (3) in sequence and is fixed by the fixing nut (10).

4. The ion beam tiltable sample stage according to claim 3, characterized in that: The pressing sheet (5), the spring sheet (4) and the sample holder (3) are provided with two sets of second fixing screws (9) and fixing nuts (10).

5. The ion beam tiltable sample stage according to claim 1, characterized in that: Gaskets are provided on both sides of the sample holder (3) on the central axis (6).

6. The ion beam tiltable sample stage according to claim 5, characterized in that: The spacers are provided in at least four pieces and at least one piece is provided on each side.

7. A processing and testing method for an ion beam tiltable sample stage according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: Perform EBSD test on the sample surface to clarify the spatial orientation of the target grain in the sample. The EBSD result can show the angle between the grain and the XYZ axis of the macro sample position; Step 2: break the vacuum, open the sample chamber, and rotate the sample holder (3) to the desired angle with the vertical axis; Step 3: Close the sample chamber and evacuate it. After the vacuum is established, turn on the electron beam to find the sample position and process it using the conventional FIB processing TEM sample method. Step 4: break the vacuum, open the sample chamber, and rotate the sample holder (3) to the desired angle with the vertical; Step 5: Close the sample chamber and evacuate the chamber. After the chamber is evacuated, turn on the electron beam to find the sample position, extend the EBSD probe into the designated position, and perform the EBSD test of the transmission beam.

Images