Processing method of transmission electron microscope test piece and transmission electron microscope test piece

Abstract

The invention relates to a processing method of a transmission electron microscope test piece and the transmission electron microscope test piece, the transmission electron microscope test piece comprises a plurality of holes arranged at intervals, the inner wall of each hole is provided with a diffusion barrier layer comprising a multi-layer structure, and the processing method comprises the following steps: arranging a first protection layer on the surface of the diffusion barrier layer; a reserved area is divided in the hole, a first edge line and a second edge line which are oppositely arranged are divided in the reserved area, the reserved area comprises two arc-shaped sections located on the edge of the hole, and the first edge line and the second edge line are connected between the two arc-shaped sections; cutting the transmission electron microscope test piece from the outer side of the reserved area to the first edge line; cutting the transmission electron microscope test piece from the outer side of the reserved area to a second edge line; a remaining portion of the first protective layer is removed. Thus, the cross section of the hole can be exposed, layering of the diffusion barrier layer on the surface of the inner wall of the hole can be observed, the boundary between multiple layers is more obvious, the coating condition of the diffusion barrier layer can be checked more easily, and whether the coating missing phenomenon exists or not can be judged.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor technology, and more specifically, to a method for processing a transmission electron microscope (TEM) specimen and a TEM specimen. Background Technology

[0002] In transmission electron microscopy (TEM) specimens, the pores are coated with a diffusion barrier layer. This diffusion barrier layer includes at least a tantalum layer or tantalum oxide layer covering the inner wall of the pores, and a copper sub-crystal layer above the tantalum layer or tantalum oxide layer. However, in traditional TEM specimen processing methods, the specimens cannot be cut thin, making it difficult to distinguish the interface between the tantalum layer (or tantalum nitride layer) and the copper sub-crystal layer. This makes it impossible to determine the coating condition of the diffusion barrier layer, potentially leading to partial incomplete coating. This can affect device operation and result in a low specimen yield. Summary of the Invention

[0003] The purpose of this disclosure is to provide a method for processing transmission electron microscopy (TEM) specimens and TEM specimens to solve the problem of unclear diffusion barrier layer layering, thereby reducing the possibility of partial missing coating of the diffusion barrier layer and improving the specimen yield.

[0004] To achieve the above objectives, this disclosure provides a method for processing a transmission electron microscope (TEM) specimen. The TEM specimen includes a plurality of spaced-apart holes, and the inner wall of each hole is provided with a diffusion barrier layer comprising a multilayer structure. The processing method includes: A first protective layer is provided on the surface of the diffusion barrier layer; A retention area is defined in the hole, and a first edge line and a second edge line are defined in the retention area. The retention area includes two arc-shaped segments located at the edge of the hole, and the first edge line and the second edge line are connected between the two arc-shaped segments. Cut the transmission electron microscope specimen from the outside of the reserved area down to the first edge line; Cut the transmission electron microscope specimen from the outside of the reserved area down to the second edge line; Remove the remaining portion of the first protective layer.

[0005] Optionally, the centers of the plurality of holes are located on the same straight line extending along the X direction, and the processing method includes: The first edge line and the second edge line are both arranged at intervals along the Y direction and extend in the X direction, wherein the X direction is perpendicular to the Y direction.

[0006] Optionally, prior to the step of cutting the transmission electron microscope specimen from the outside of the reserved area down to the second edge line, the processing method includes: Record the coordinates corresponding to the positions of the center lines of the multiple holes; A compensation layer is applied to the outside of the hole located at the first edge line; Rotate the transmission electron microscope specimen 180° in the XY plane direction; Move the transmission electron microscope specimen to align the center lines of the multiple holes with the coordinates.

[0007] Optionally, after the step of applying a compensation layer to the outside of the hole located on the first edge line, the processing method includes: A second protective layer is applied to the surface of the first protective layer and the surface of the compensation layer adjacent to the first protective layer.

[0008] Optionally, in the step of coating the surface of the first protective layer and the surface of the compensation layer adjacent to the first protective layer with a second protective layer, the processing method includes: An adhesive layer is applied to the surface of the first protective layer and the surface of the compensation layer near the first protective layer; A second platinum layer is coated on the surface of the adhesive layer.

[0009] Optionally, after the step of cutting the transmission electron microscope specimen from the outside of the reserved area to the second edge line, the processing method includes: Rotate the transmission electron microscope specimen 180° in the XY plane direction; Move the transmission electron microscope specimen to align the center lines of the multiple holes with the coordinates; Remove the compensation layer and the second protective layer on the surface of the compensation layer; Remove the remaining portions of the first and second protective layers.

[0010] Optionally, in the step of dividing a reserved area in the hole, and dividing the reserved area into a first edge line and a second edge line that are disposed opposite to each other, the processing method includes: Align the first edge line with the center line of the hole.

[0011] Optionally, in the step of coating the surface of the diffusion barrier layer with a surface-cured first protective layer, the processing method includes: Organic pigments are filled into the pores to form a filling layer; A first platinum layer is applied to the surface of the filler layer.

[0012] Optionally, the processing method includes: A cutting hole is drilled through the first platinum layer on the outer side of the reserved area, wherein the cutting hole is close to the first edge line; Cut the transmission electron microscope specimen from the edge of the cutting hole along a direction perpendicular to the first edge line until the first edge line is reached.

[0013] Optionally, the processing method includes: The transmission electron microscope specimens were cut using a focused ion beam.

[0014] According to another aspect of this disclosure, a transmission electron microscope (TEM) slide processed by the described transmission electron microscope (TEM) slide processing method is provided.

[0015] By cutting the transmission electron microscope (TEM) specimen from both sides using the above technical solution, the thickness of the TEM specimen can be effectively reduced to 50nm-80nm, thereby improving the yield of the TEM specimen. Furthermore, cutting at the location of the holes exposes the cross-section of the holes, making it easier to observe the layered structure of the diffusion barrier layer on the inner surface of the holes. This makes the boundaries between the multiple layers of the diffusion barrier layer more distinct, facilitating the inspection of the diffusion barrier layer coating and identifying any missed coatings. Based on the inspection findings, the diffusion barrier layer can be recoated promptly, minimizing the impact on device operation and further improving the yield of the TEM specimen.

[0016] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a top view of a transmission electron microscope specimen according to one embodiment of the present disclosure.

[0018] Figure 2 This is a cross-sectional view of a transmission electron microscope specimen according to one embodiment of the present disclosure.

[0019] Figure 3 This is a cross-sectional view of a transmission electron microscope specimen according to one embodiment of the present disclosure from another perspective.

[0020] Figure 4 This is a schematic diagram of a transmission electron microscope specimen coated with a first protective layer according to one embodiment of the present disclosure.

[0021] Figure 5 This is a schematic diagram of a transmission electron microscope specimen cut to a first edge line according to one embodiment of the present disclosure.

[0022] Figure 6 This is a cross-sectional view of a transmission electron microscope specimen coated with a second protective layer according to one embodiment of the present disclosure.

[0023] Figure 7 This is a schematic diagram of a transmission electron microscope specimen cut to the second edge line according to one embodiment of the present disclosure.

[0024] Figure 8 This is a schematic diagram of a transmission electron microscope specimen with the compensation layer and a portion of the second protective layer and compensation layer removed according to one embodiment of the present disclosure.

[0025] Figure 9 This is a schematic diagram of a transmission electron microscope specimen with the first and second protective layers removed according to one embodiment of the present disclosure.

[0026] Figure 10 This is a flowchart of a method for processing transmission electron microscope (TEM) specimens according to one embodiment of the present disclosure.

[0027] Figure 11 This is a flowchart of a method for processing transmission electron microscope specimens according to another embodiment of the present disclosure.

[0028] Explanation of reference numerals in the attached figures 1-Transmission electron microscopy specimen; 10-Reserved area; 11-Pore; 12-Diffusion barrier layer; 121-Tantalum layer; 122-Copper seed crystal layer; 13-First edge line; 14-Second edge line; 15-Compensation line; 2-First protective layer; 21-Filling layer; 22-First platinum layer; 3-Compensation layer; 4-Second protective layer; 41-Adhesive layer; 42-Second platinum layer. Detailed Implementation

[0029] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0030] In this disclosure, unless otherwise stated, directional terms such as "inner" and "outer" are defined in relation to the outline of the corresponding components. The terms "first," "second," etc., are used to distinguish different components and are not sequential or significant. Furthermore, in the following description, when referring to the accompanying drawings, unless otherwise explained, the same reference numerals in different drawings denote the same or similar elements.

[0031] According to one embodiment of this disclosure, such as Figures 1 to 10As shown, a method for processing a transmission electron microscope (TEM) specimen is provided. The TEM specimen 1 includes a plurality of spaced holes 11, and the inner wall of the holes 11 is provided with a diffusion barrier layer 12 having a multilayer structure. Here, the diffusion barrier layer 12 may include at least a tantalum layer 121 covering the inner wall of the holes 11 and a copper sub-crystal layer 122 covering the outer side of the tantalum layer 121. The tantalum layer 121 may be composed of pure tantalum with a thickness of 10 nm or tantalum nitride with a thickness of 15 nm to 20 nm, which is not limited in this disclosure. After the TEM specimen 1 is sorted, the processing method may first perform step 1001, that is, provide a first protective layer 2 on the surface of the diffusion barrier layer 12, and then perform step 1002, dividing a retention area 10 in the holes 11, and dividing a first edge line 13 and a second edge line 14 oppositely arranged in the retention area 10. The retention area 10 may include two arc-shaped segments located at the edge of the holes 11, and the first edge line 13 and the second edge line 14 are connected between the two arc-shaped segments. After the retention area 10 and the first protective layer 2 are both set, step 1003 can be executed, that is, cutting can be started from one side of the retention area 10. Specifically, the transmission electron microscope specimen 1 can be cut from the outside of the retention area 10 to the first edge line 13. After the cutting on this side is completed, step 1004 can be executed, that is, cutting can be started from the other side of the retention area 10. Specifically, the transmission electron microscope specimen 1 can be cut from the outside of the retention area 10 to the second edge line 14. After both sides are cut, step 1005 can be executed to remove the remaining part of the first protective layer 2.

[0032] By cutting the transmission electron microscope (TEM) specimen 1 from both sides using the above technical solution, the thickness of the TEM specimen 1 can be effectively reduced to 50nm-80nm, thereby improving the yield of the TEM specimen 1. Furthermore, cutting at the location of the hole 11 exposes the cross-section of the hole 11, allowing for easier observation of the layered structure of the diffusion barrier layer 12 on the inner wall surface of the hole 11. This makes the boundaries between the multiple layers of the diffusion barrier layer 12 more distinct, facilitating inspection of the coating condition of the diffusion barrier layer 12 and identifying any missed coatings. Based on the inspection results, the diffusion barrier layer 12 can be recoated promptly, reducing the impact on device operation and improving the yield of the TEM specimen 1.

[0033] It should be noted that two compensation lines 15 can also be divided on the outer side of the retention area 10. The two compensation lines 15 are respectively spaced apart from the first edge line 13 and the second edge line 14. When performing steps 1003 and 1004, the cutting can be performed first to the position of the compensation line 15, and then the part between the corresponding compensation line 15 and the first edge line 13 or the second edge line 14 can be gradually removed in subsequent processes to correct the position to the first edge line 13 and the second edge line 14, so as to reduce the situation of excessive cutting, thereby affecting the quality of the transmission electron microscope specimen 1. In addition, in the transmission electron microscope specimen processing method of this disclosure, the transmission electron microscope specimen 1 can be cut by a focused ion beam. The specimen is cut into the target shape by bombarding the transmission electron microscope specimen 1 with the ion beam. The ion source of the ion beam can be gallium ions, helium ions, or neon ions. This disclosure does not limit the use of these. When the transmission electron microscope specimen 1 is cut by bombardment with a focused ion beam, the first protective layer 2 protects the transmission electron microscope specimen 1 and prevents the hole 11 from collapsing during the bombardment process, thereby damaging the specimen and rendering it unusable.

[0034] Furthermore, such as Figures 1 to 3 As shown, the centers of the multiple holes 11 can be located on the same straight line extending along the X direction. In the processing method of the transmission electron microscope (TEM) specimen, step 1101 can be included, where the first edge line 13 and the second edge line 14 can be arranged at intervals along the Y direction and extend along the X direction, wherein the X direction and the Y direction are perpendicular. Thus, when performing steps 1003 and 1004, portions of the TEM specimen 1 corresponding to the positions of the multiple holes 11 can be cut at once, improving cutting efficiency.

[0035] Furthermore, such as Figure 6 and Figure 11 As shown, before the step of cutting the transmission electron microscope specimen 1 from the outside of the retention area 10 to the second edge line 14, the processing method includes step 1107, recording the coordinates corresponding to the positions of the center lines of the holes 11, and then performing step 1108, coating a compensation layer 3 on the outside of the holes 11 located on the first edge line 13. The function of the compensation layer 3 is to fill the cut portion on this side, which can both protect this side in the subsequent cutting process and facilitate auxiliary positioning in subsequent steps. After the compensation layer 3 is coated, the second protective layer 4 can be coated first, or step 1111 can be performed directly, that is, rotating the transmission electron microscope specimen 1 180° in the XY plane direction, and then performing step 1112 to move the transmission electron microscope specimen 1, aligning the center lines of the holes 11 with the coordinates. The purpose of this step is to accurately correspond the cutting position and prevent over-cutting or insufficient cutting. After the position is aligned, the compensation layer 3 can assist in positioning in the Y direction to further ensure that the center lines of the holes can be aligned with the coordinates.

[0036] Here, as Figure 1 and Figure 11 As shown, the processing method may further include step 1104, which involves dividing the hole 11 into a retention area 10, and dividing the retention area 10 into a first edge line 13 and a second edge line 14 that are set opposite to each other, by aligning the first edge line 13 with the center line of the hole. That is, the first side should be cut to the middle position to facilitate subsequent cutting and positioning.

[0037] According to one embodiment of this disclosure, such as Figure 11 As shown, after performing step 1108, the processing method may further include coating a second protective layer 4 onto the surface of the first protective layer 2 and the surface of the compensation layer 3 near the first protective layer 2. The function of the second protective layer 4 is also to protect the pores 11 during ion beam bombardment, preventing the collapse of the pores 11 from affecting the sample yield. The second protective layer 4 can also be a single-layer or multi-layer structure; this disclosure does not limit this. Specifically, taking a multi-layer structure as an example, such as... Figure 6 As shown, when setting the second protective layer 4, step 1109 can be performed, that is, applying an adhesive layer 41 to the surface of the first protective layer 2 and the surface of the compensation layer 3 near the first protective layer 2, so as to Figure 6 Taking the image orientation as an example, in transmission electron microscope sample 1 with... Figure 6 When positioned in the correct orientation, the adhesive layer 41 can be located above the first protective layer 2 and the compensation layer 3. After the adhesive layer 41 is applied, step 1110 can be performed to apply a second platinum layer 42 to the surface of the adhesive layer 41 to protect the hole 11. Here, the adhesive layer 41 can be coated with epoxy resin adhesive, or other adhesives can be used; this disclosure does not limit the choice.

[0038] According to one embodiment of this disclosure, such as Figures 7 to 11As shown, after the step of cutting the transmission electron microscope specimen 1 from the outside of the retention area 10 to the second edge line 14, the processing method may include step 1113, which involves rotating the transmission electron microscope specimen 1 180° in the XY plane direction, and then performing step 1114, moving the transmission electron microscope specimen 1 to align the center lines of the multiple holes 11 with the coordinates. This step is to ensure precise alignment of the cutting position and prevent over-cutting or under-cutting. After the position is aligned, the compensation layer 3 can be used to assist in positioning in the Y direction to further ensure that the center lines of the holes can be aligned with the coordinates. After the transmission electron microscope specimen 1 is moved to the target position, step 1115 is performed to remove the compensation layer 3 and the second protective layer 4 on the surface of the compensation layer 3. Since the material of the compensation layer 3 is also the same epoxy resin as the adhesive layer 41, and the epoxy resin will affect the image of the transmission electron microscope, the compensation layer 3 needs to be removed. Matching the center lines of the holes with the coordinates can also assist in the positioning of the compensation layer 3, so as to accurately remove the compensation layer 3. After the compensation layer 3 is removed, step 1116 is performed to remove the remaining parts of the first protective layer 2 and the second protective layer 4 to complete the fabrication of the transmission electron microscope specimen 1.

[0039] According to one embodiment of this disclosure, such as Figure 4 and Figure 11As shown, in the step of coating the surface of the diffusion barrier layer 12 with the first protective layer 2 that has been surface cured, the processing method may further include step 1102, that is, filling the gaps in the holes 11 with organic pigment to form a filling layer 21. Here, the organic pigment can be filled with marker ink, that is, using a marker to apply ink to the position of the holes 11 so that the ink penetrates into the holes 11 to complete the filling. After the filling is completed, step 1103 can be performed, that is, covering the surface of the filling layer 21 with a first platinum layer 22 to complete the protection of the holes 11 and prevent the holes 11 from being damaged during ion beam bombardment cutting. Here, the organic pigment used in the filler layer 21 ensures that the liquid filler can fully fill the pores 11, preventing gaps from forming in the pores 11. The first platinum layer 22 protects the pores 11 from damage caused by ion beam bombardment. During ion beam bombardment, the ion beam diffuses to the surrounding area of ​​the cutting position. Therefore, covering with the first platinum layer 22 provides protection, preventing excessive ion beam bombardment from causing the pores 11 to collapse and affecting the yield of the transmission electron microscope specimen 1. Here, the thickness of both the first platinum layer 22 and the second platinum layer 42 mentioned above can be 8μm to 10μm, and this disclosure does not limit this. In addition, since platinum is a solid and has no fluidity, if the first platinum layer 22 is directly covered without filling, it is also easy for the underlying pores to collapse, thus losing its protective function for the pores 11. Therefore, it is necessary to fill first and then cover with the first platinum layer 22 to achieve a better protective effect. Of course, the first protective layer 2 can also be a curable fluid resin material that is directly filled into the hole 11 and then covered to the surface of the opening of the hole 11. After filling, the resin is cured to provide both filling and protection effects. This disclosure does not limit this.

[0040] Furthermore, such as Figure 11 As shown, the processing method may further include step 1105, which involves excavating a cutting hole penetrating the first platinum layer 22 on the outer side of the reserved area 10. The cutting hole is located near the first edge line 13. Here, the cutting hole serves to facilitate confirmation of the initial cutting position and can act as a positioning tool. After the cutting hole is excavated, step 1006 is executed, cutting the transmission electron microscope specimen 1 from the edge of the cutting hole along a direction perpendicular to the first edge line 13 until the first edge line 13 is reached, thus completing the cutting on the first side.

[0041] Based on the above-mentioned solution, this disclosure also provides a transmission electron microscope (TEM) specimen, which is processed using the above-mentioned TEM specimen processing method and has all the beneficial effects of the above-mentioned TEM specimen processing method, which will not be elaborated here.

[0042] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0043] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0044] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method of processing a transmission electron microscope specimen, characterized by, The transmission electron microscope sample includes a plurality of spaced-apart holes, inner walls of the holes are provided with a diffusion barrier layer including a multilayer structure, the processing method includes: A first protective layer is provided on the surface of the diffusion barrier layer; A reserved area is divided in the hole, and a first edge line and a second edge line are oppositely arranged in the reserved area, wherein the reserved area includes two arc segments located at the edges of the hole, and the first edge line and the second edge line are connected between the two arc segments; The transmission electron microscope sample is cut from the outside of the reserved area until the first edge line; The transmission electron microscope sample is cut from the outside of the reserved area until the second edge line; The remaining part of the first protective layer is removed.

2. The method of claim 1, wherein The centers of the plurality of holes are located on the same straight line extending in the X direction, and the processing method includes: The first edge line and the second edge line are both arranged in the Y direction and extend in the X direction, and the X direction and the Y direction are perpendicular.

3. The method of claim 2, wherein the method further comprises: Before the step of cutting the transmission electron microscope sample from the outside of the reserved area until the second edge line, the processing method includes: Coordinates corresponding to the positions of the hole center lines where the centers of the plurality of holes are located are recorded; A compensation layer is coated on the outside of the hole located at the first edge line; The transmission electron microscope sample is rotated by 180° in the XY plane direction; The transmission electron microscope sample is moved to align the hole center lines of the plurality of holes with the coordinates.

4. The method of claim 3, wherein the method further comprises: After the step of coating the compensation layer on the outside of the hole located at the first edge line, the processing method includes: A second protective layer is coated on the surface of the first protective layer and the surface of the compensation layer close to the first protective layer.

5. The method of claim 4, wherein the method further comprises: In the step of coating the second protective layer on the surface of the first protective layer and the surface of the compensation layer close to the first protective layer, the processing method includes: A glue layer is coated on the surface of the first protective layer and the surface of the compensation layer close to the first protective layer; A second platinum layer is coated on the surface of the glue layer.

6. The method of claim 4, wherein the step of applying a voltage to the TEM sample is performed by applying a voltage of between 0.1 and 10 volts to the TEM sample. After the step of cutting the transmission electron microscope sample from the outside of the reserved area until the second edge line, the processing method includes: The transmission electron microscope sample is rotated by 180° in the XY plane direction; The transmission electron microscope sample is moved to align the hole center lines of the plurality of holes with the coordinates; The compensation layer and the second protective layer on the surface of the compensation layer are cut off; The remaining part of the first protective layer and the second protective layer is removed.

7. The method of claim 3, wherein the method further comprises: In the step of dividing a reserved area in the hole, and oppositely arranging a first edge line and a second edge line in the reserved area, the processing method includes: The first edge line coincides with the hole center line.

8. The method of claim 1, wherein In the step of coating the first protective layer on the surface of the diffusion barrier layer, the processing method includes: The interstices in the hole are filled with organic pigments to form a filling layer; A first platinum layer is coated on the surface of the filling layer.

9. The method of claim 8, wherein the method further comprises: The processing method includes: a cut hole penetrating the first platinum layer is dug outside the reserved area, wherein the cut hole is close to the first edge line; the TEM sample is cut from the edge of the cut hole in a direction perpendicular to the first edge line until the first edge line.

10. The method of handling a transmission electron microscope specimen according to any one of claims 1 to 9, wherein, The processing method comprises: The TEM sample is cut by a focused ion beam.

11. A TEM sample processed by the processing method of the TEM sample according to any one of claims 1-10.

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