Method for fixing FIB grid of transmission electron microscope

Abstract

A method for fixing a transmission electron microscope FIB grid comprises the following steps: 1) thinning a TEM sample, and placing the TEM sample on qualitative filter paper; 2) cutting silica gel, wherein the length of the silica gel is greater than the side length of the storage box, and the width is less than or equal to the side length of the storage box; the cut silica gel is placed in a storage box; (3) cutting a gap penetrating through the upper edge and the lower edge of the silica gel in the width direction by using a wallpaper knife at the central position of the silica gel in the length direction; 4) carrying out reverse folding, and placing the FIB grid in the gap; (5) the silica gel clamping the FIB carrying net is stably placed in a storage box; (6) the storage box is placed in a vacuum bag, and vacuumizing treatment is conducted; and the stability of the FIB grid in the transportation process is further ensured, so that the whole operation process is completed. The device has the advantages that the TEM sample welded on the FIB carrier net can be suspended on the surface of the silica gel, and the FIB carrier net can be stably clamped in the silica gel under the action of the stress of the silica gel; the FIB carrier net is clamped in the silica gel, and random transportation of the FIB carrier net is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of transmission electron microscopes, and in particular relates to a method for fixing a transmission electron microscope FIB grid. Background Art

[0002] Transmission electron microscope, also known as TEM, is an electronic optical instrument with high resolution and high magnification. It has become an extremely important analytical characterization tool in the field of materials science. With the help of TEM, not only can the structure of materials be analyzed, but also the structure of materials can be deeply explored at the nanometer and even atomic scales. If combined with an energy dispersive spectrometer (EDS), the chemical composition of the material elements can also be analyzed. When using TEM to study the morphology and structure of materials, the sample must be fixed on a dedicated grid for the electron microscope. Usually, the sample will be welded to the FIB grid with the help of a focused ion beam device (FIB-SEM) for subsequent analysis. Especially for magnetic samples, because the focused ion beam device is extremely dense and firm when welding the sample, it can ensure that the transmission sample will not drift under the TEM; in this way, high-quality images can be obtained, which provides strong support for data analysis.

[0003] The existing tools for fixing transmission electron microscope FIB grids include high-elastic film boxes or bare chip boxes, which have the following defects: the tightness of the high-elastic film boxes varies, and the FIB grid will move back and forth in the high-elastic film boxes, resulting in the loss of TEM samples welded on the FIB grid; the bare chip box has low viscosity, and the pressure-sensitive adhesive surface where the FIB grid is placed will adhere firmly, but when the FIB grid is clamped with tweezers, stress will be generated, resulting in the loss of TEM samples. Therefore, it is difficult to transport the FIB grid, and it is very easy to lose samples, thus delaying the test cycle. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for fixing a transmission electron microscope FIB grid.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a method for fixing a transmission electron microscope FIB grid, characterized in that it comprises the following steps: 1) First, use welding materials to weld the TEM sample to the top of the FIB grid, and then thin the TEM sample to ensure that the thickness of the thinned TEM sample meets the requirements of transmission electron microscopy. After thinning, take the TEM sample out of the focused ion beam (FIB-SEM) device and place it on qualitative filter paper without damaging the sample. 2) Cut the silicone of a certain thickness according to specific dimensions: the length of the silicone must be greater than the side length of the storage box, and the width of the silicone must be less than or equal to the side length of the storage box; place the cut silicone stably in the storage box. At this time, the surface of the silicone will present a certain curvature, which is convenient for clamping the FIB grid to be transported more firmly in the future, ensuring that the FIB grid will not be displaced during transportation; 3) Adjust the blade length of the wallpaper knife to be less than the thickness of the silicone. Use the wallpaper knife to cut a slit in the center of the length direction of the cut silicone. The slit should run through the upper and lower edges of the silicone in the width direction, and the depth should be controlled so as not to completely cut the silicone, to ensure the size accuracy of the slit. 4) Fold the treated silicone rubber in reverse, and the width of the gap will be Width of blade increased Width ; Then place the FIB grid in the enlarged gap; During the placement process, always keep the FIB grid and the silicone surface in a vertical state, and then slowly restore the silicone to a horizontal state; During this process, the FIB grid will adhere to one side of the silicone under the adsorption effect of the silicone. When the silicone is completely restored to a horizontal state, the FIB grid will be firmly clamped into the silicone gap, achieving the initial fixation of the grid; 5) Place the silicone holding the FIB grid steadily in the storage box: As the length of the silicone is greater than the side length of the storage box, place one end of the silicone at the bottom of the storage box, with the surface that holds the FIB grid facing the bottom of the storage box. Then, slowly place the other end of the silicone into the storage box. When the cut silicone is completely placed into the storage box, the silicone will form a concave arch structure inside the storage box, generating stress. This stress can effectively clamp the FIB grid and prevent it from falling off during transportation, thus successfully completing the placement of the grid in the storage box. 6) Place the storage box in a vacuum bag and evacuate it to ensure the stability of the FIB grid during transportation. This completes the entire operation process.

[0006] Preferably, in step 1), the welding material includes platinum (PT), carbon (C), and tungsten (W).

[0007] Preferably, in step 1), the TEM sample is taken out using tweezers or a vacuum pen.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention can make the TEM sample welded on the FIB grid suspend on the surface of the silicone, thereby ensuring that the TEM sample does not contact with any other substance, and the FIB grid will be firmly clamped in the silicone under the action of the silicone stress; by clamping the FIB grid inside the silicone in a manner of silicone stress, the TEM sample does not come into contact with any object, thereby achieving more appropriate protection for the TEM sample, and also enabling the grid to be transported at will, greatly improving the convenience of experimental operation and the safety of samples. DETAILED DESCRIPTION

[0009] The present invention will be further described below in conjunction with embodiments: Example

[0010] A method for fixing a transmission electron microscope FIB grid comprises the following steps: 1) First, weld the TEM sample to the top of the FIB grid with platinum (PT) or carbon (C), and then thin the TEM sample to ensure that the thickness of the thinned TEM sample is less than 100nm; after thinning, take the TEM sample out of the focused ion beam (FIB-SEM) device with tweezers and place it on qualitative filter paper without damaging the sample; 2) Cut the silicone with a thickness greater than 3 mm according to specific sizes: the length of the silicone must be greater than the side length of the storage box. For example, for a 2.3mm small-sized storage box, the length of the silicone is 2.8mm; the width of the silicone must be less than or equal to the side length of the storage box. Taking a 2.3mm small-sized storage box as an example, the width of the silicone is 2-2.3mm; Place the cut silicone stably in the storage box. At this time, the surface of the silicone will present a certain curvature, which is convenient for clamping the FIB grid to be transported more firmly in the future, ensuring that the FIB grid will not be displaced during transportation; 3) Adjust the blade length of the wallpaper knife to 2-2.5mm accurately; use the wallpaper knife to cut a slit in the center of the length direction of the cut silicone. The slit must pass through the upper and lower edges of the silicone in the width direction, and the depth must be controlled between 2-2.5mm, and the slit width is set to 0.1mm; ensure the dimensional accuracy of the slit; 4) Fold the treated silicone rubber in reverse, and the width of the gap will increase from 0.1mm to 0.5mm; then place the FIB grid in the increased gap; during the placement process, always keep the FIB grid and the silicone surface in a vertical state, and then slowly restore the silicone rubber to a horizontal state; during this process, the FIB grid will adhere to one side of the silicone rubber under the adsorption effect of the silicone rubber. When the silicone rubber is completely restored to a horizontal state, the FIB grid will be firmly clamped into the silicone gap, achieving the initial fixation of the grid; 5) Place the silicone holding the FIB grid steadily in the storage box: As the length of the silicone is greater than the side length of the storage box, place one end of the silicone at the bottom of the storage box, with the surface that holds the FIB grid facing the bottom of the storage box. Then, slowly place the other end of the silicone into the storage box. When the cut silicone is completely placed into the storage box, the silicone will form a concave arch structure inside the storage box, generating stress. This stress can effectively clamp the FIB grid and prevent it from falling off during transportation, thus successfully completing the placement of the grid in the storage box. 6) Place the storage box in a vacuum bag and evacuate it to ensure the stability of the FIB grid during transportation. This completes the entire operation process.

[0011] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A method for fixing a transmission electron microscope FIB grid, characterized in that: The steps include: 1) First, use welding materials to weld the TEM sample to the top of the FIB grid, and then thin the TEM sample to ensure that the thickness of the thinned TEM sample meets the requirements of transmission electron microscopy; After the thinning is completed, the TEM sample is taken out from the focused ion beam (FIB-SEM) device and placed on a qualitative filter paper without damaging the sample; 2) Cut the silicone of a certain thickness according to specific dimensions: the length of the silicone must be greater than the side length of the storage box, and the width of the silicone must be less than or equal to the side length of the storage box; place the cut silicone stably in the storage box. At this time, the surface of the silicone will present a certain curvature, which is convenient for clamping the FIB grid to be transported more firmly in the future, ensuring that the FIB grid will not be displaced during transportation; 3) Adjust the blade length of the wallpaper knife to be less than the thickness of the silicone. Use the wallpaper knife to cut a slit in the center of the length direction of the cut silicone. The slit should run through the upper and lower edges of the silicone in the width direction, and the depth should be controlled so as not to completely cut the silicone, to ensure the size accuracy of the slit. 4) Fold the treated silicone rubber in reverse, and the width of the above-mentioned gap will be widened from the width of the blade; then place the FIB grid in the enlarged gap; during the placement process, always keep the FIB grid and the silicone surface in a vertical state, and then slowly restore the silicone to a horizontal state; during this process, the FIB grid will adhere to one side of the silicone rubber under the adsorption effect of the silicone rubber. When the silicone rubber is completely restored to a horizontal state, the FIB grid will be firmly clamped into the silicone gap, achieving the initial fixation of the grid; 5) Place the silicone holding the FIB grid steadily in the storage box: Since the length of the silicone is greater than the side length of the storage box, first place one end of the silicone at the bottom of the storage box, with the surface that holds the FIB grid facing the bottom of the storage box. Then, slowly place the other end of the silicone into the storage box. When the cut silicone is completely placed into the storage box, the silicone will form a concave arch structure inside the storage box, thereby generating stress. This stress can effectively clamp the FIB grid and prevent it from falling off during transportation, thus successfully completing the placement of the grid in the storage box. 6) Place the storage box in a vacuum bag and evacuate it to ensure the stability of the FIB grid during transportation. This completes the entire operation process.

2. The method for fixing a transmission electron microscope FIB grid according to claim 1, characterized in that: Step 1), the welding material includes platinum (PT), carbon (C), and tungsten (W).

3. The method for fixing a transmission electron microscope FIB grid according to claim 2, characterized in that: Step 1) Use tweezers or a vacuum pen to remove the TEM sample.