Wafer sample preparation equipment and sample preparation method

Abstract

The invention provides sample preparation equipment and a sample preparation method of a wafer. The sample preparation equipment comprises a carrying table, a mask plate, a moving device and an ion implantation device, the carrying table is used for carrying a silicon carbide wafer, the mask plate is arranged on one side, carrying the silicon carbide wafer, of the carrying table, the mask plate comprises an opening, at least part of the orthographic projection of the opening on the carrying table is located in the range of the orthographic projection of the silicon carbide wafer on the carrying table, and the moving device is used for controlling the mask plate and the carrying table to move relatively. The ion implantation device is arranged on the side, away from the carrying table, of the mask plate, the ion implantation device is used for implanting ions into the silicon carbide wafer through the opening of the mask plate, and the purpose of reducing the sample preparation cost of the silicon carbide wafer and improving the sample preparation efficiency of the silicon carbide wafer is achieved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a wafer sample preparation device and a sample preparation method. Background Art

[0002] In the semiconductor manufacturing process, it is very important to control the concentration of dopants and their distribution in the wafer, which directly affects the performance of the semiconductor devices prepared later. In order to analyze the doping elements in the wafer after ion implantation to determine whether the wafer has the ability to form an ion implantation area, the wafer is usually sampled and then the obtained wafer sample is analyzed by secondary ion mass spectrometry (SIMS).

[0003] However, the current steps for wafer sample preparation are complicated, the sample preparation cycle is long, the efficiency is low, and the sample preparation cost is high. Summary of the invention

[0004] The present application provides a wafer sample preparation device and a sample preparation method. The sample preparation device is simple to operate, has a short sample preparation cycle, high efficiency, and effectively reduces the sample preparation cost.

[0005] To achieve the above objectives, the embodiments of the present application provide the following technical solutions:

[0006] On the one hand, a wafer sample preparation device is provided, which includes a stage, a mask, a moving device and an ion implantation device. The stage is used to carry a silicon carbide wafer, the mask plate is arranged on the side of the stage that carries the silicon carbide wafer, the mask plate includes an opening, and the orthographic projection of the opening on the stage is at least partially located within the range of the orthographic projection of the silicon carbide wafer on the stage, the moving device is used to control the relative movement of the mask plate and the stage, the ion implantation device is arranged on the side of the mask plate away from the stage, and the ion implantation device is used to implant ions into the silicon carbide wafer through the opening of the mask plate.

[0007] In the wafer sample preparation device, the relative movement of the mask plate and the stage is controlled by a moving device, so that the opening on the mask plate is aligned with the preset sample preparation area of ​​the silicon carbide wafer, and then the ion implantation device is used to implant ions into the silicon carbide wafer through the opening of the mask plate to form a sample preparation area. Since the moving device can control the relative movement of the mask plate and the stage, the ion implantation area of ​​the silicon carbide wafer can be adjusted by adjusting the relative position of the mask plate and the silicon carbide wafer set on the stage, so as to form multiple sample preparation areas on the silicon carbide wafer, thereby reducing the sample preparation cost. The sample preparation device is simple to operate, has a short sample preparation cycle, and has a high sample preparation efficiency.

[0008] In some embodiments, the silicon carbide wafer includes multiple sample preparation areas, at least two sample preparation areas have different ion implantation parameters, and the area of ​​the orthographic projection of the opening of the mask plate on the carrier is smaller than the area of ​​the orthographic projection of the silicon carbide wafer on the carrier, and is greater than or equal to the area of ​​the orthographic projection of the sample preparation area on the carrier.

[0009] In some embodiments, the shape of the orthographic projection of the opening of the mask plate on the carrier is one of a rectangle, a square, a circle or a sector.

[0010] In some embodiments, the shape of the orthographic projection of the opening of the mask plate on the carrier is a square, and the side length of the square is greater than or equal to 8 mm.

[0011] In some embodiments, the moving device includes a first moving device and a second moving device, the first moving device is connected to the mask plate, the first moving device is used to control the mask plate to move in a direction parallel to the carrier, so that the mask plate moves relative to the carrier, and the second moving device is connected to the carrier, the second moving device is used to control the carrier and the silicon carbide wafer to move in a direction parallel to the mask plate, so that the carrier and the silicon carbide wafer move relative to the mask plate.

[0012] On the other hand, a wafer sample preparation method is provided, which includes placing a silicon carbide wafer on a carrier, arranging a mask plate on a side of the carrier that supports the silicon carbide wafer, the mask plate including an opening, the orthographic projection of the opening on the carrier being at least partially located within the range of the orthographic projection of the silicon carbide wafer on the carrier, controlling the mask plate and the carrier to perform a first relative movement, and then performing a first ion implantation into the silicon carbide wafer through the opening of the mask plate to form a first sample preparation area.

[0013] In the above-mentioned sample preparation method, the mask plate and the carrier are controlled to move relative to each other for the first time, so that the opening on the mask plate is aligned with the partial area of ​​the silicon carbide wafer, and then ions are injected into the silicon carbide wafer through the opening of the mask plate by the ion implantation device to form the first sample preparation area. By controlling the mask plate and the carrier to move relative to each other for the first time and adjusting the relative position of the mask plate and the silicon carbide wafer, the ion implantation area of ​​the silicon carbide wafer can be adjusted to form multiple sample preparation areas on the silicon carbide wafer, thereby reducing the sample preparation cost. The sample preparation method has a short sample preparation cycle and a high sample preparation efficiency.

[0014] In some embodiments, controlling the mask plate and the stage to perform a first relative movement includes controlling the mask plate to perform a first movement in a direction parallel to the stage, or controlling the stage to perform a first movement in a direction parallel to the mask plate, or controlling the mask plate to perform a first movement in a direction parallel to the stage, and controlling the stage to perform a first movement in both directions parallel to the mask plate.

[0015] In some embodiments, after the first ion implantation, the sample preparation method further includes controlling the mask plate and the carrier to perform a second relative movement, and performing a second ion implantation into the silicon carbide wafer through the opening of the mask plate to form a second sample preparation area, wherein the orthographic projection of the second sample preparation area on the carrier does not overlap with the orthographic projection of the first sample preparation area on the carrier, and the ion implantation parameters of the second sample preparation area are different from those of the first sample preparation area.

[0016] In some embodiments, the mask plate is disposed on a side of the stage that supports the silicon carbide wafer, including controlling the mask plate to move in a direction parallel to the stage so that the mask plate is located on the side of the stage that supports the silicon carbide wafer.

[0017] In some embodiments, the first sample preparation area obtained using the above-mentioned sample preparation method is analyzed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present application, the following is a brief introduction to the drawings required for use in some embodiments of the present application. Obviously, the drawings described below are only drawings of some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not limitations on the actual size of the products involved in the embodiments of the present application, the actual process of the method, etc.

[0019] Figure 1 A diagram showing the steps of preparing a wafer sample in the related art;

[0020] Figure 2 A schematic diagram of the structure of a sample preparation device provided in an embodiment of the present application;

[0021] Figure 3 Another structural schematic diagram of the sample preparation device provided in the embodiment of the present application;

[0022] Figure 4 A diagram of the shape of the openings on the mask provided in an embodiment of the present application;

[0023] Figure 5 A schematic diagram of a sample preparation area of ​​a silicon carbide wafer in an embodiment of the present application;

[0024] Figure 6 A flow chart of the steps of the sample preparation method provided in the embodiment of the present application;

[0025] Figure 7 to Figure 10 for Figure 6 The diagrams of the steps in

[0026] Fig.11 for Figure 6 The flow chart of steps after step S4 of the sample preparation method shown;

[0027] Figure 12-13 for Fig.11 The steps in the diagram. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0029] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0030] In the description of the present application, “plurality” means two or more.

[0031] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0032] Before the silicon carbide wafer is subjected to ion implantation and other processes to form semiconductor devices, in order to ensure the quality of the semiconductor devices formed subsequently, monitor the stability of the production process, and improve the yield rate of the final product, it is necessary to perform sample testing on the silicon carbide wafer. Commonly used sample testing technologies include secondary ion mass spectrometry (SIMS) technology, which performs surface analysis on silicon carbide wafer samples that have been ion implanted under certain conditions to obtain a spectrum of sample surface information.

[0033] Figure 1 The following is a step diagram of wafer sample preparation in the related art, such as Figure 1As shown, the sample preparation process of the silicon carbide wafer includes: first depositing a layer of silicon oxide (film formation) on the surface of the silicon carbide wafer, and then coating the side of the silicon oxide away from the wafer surface with photoresist, after exposure and development to remove the photoresist in a quarter sector, etching the exposed silicon oxide in a quarter sector and the remaining photoresist until the surface of the wafer in a quarter sector is exposed, and then using silicon oxide as a mask to perform ion implantation under certain conditions on the surface of the wafer in a quarter sector, and finally etching away the remaining silicon oxide to obtain a sample preparation area A. Repeating the above steps three times can obtain four sample preparation areas A, sample preparation area B, sample preparation area C and sample preparation area D in a quarter sector.

[0034] It can be seen that the steps of wafer sample preparation in the related art are complicated, the sample preparation cycle is long, and a wafer can only obtain four samples at most, which increases the cost of the sample preparation process. To solve the above problems, the embodiment of the present application provides a wafer sample preparation device and a sample preparation method.

[0035] Figure 2 A schematic diagram of the structure of the sample preparation device provided in the embodiment of the present application, such as Figure 2 As shown, the sample preparation device 1 includes a stage 11, a mask plate 12, a moving device 13 and an ion implantation device 14. The stage 11 is used to carry a silicon carbide wafer 15, wherein the stage 11 can fix the silicon carbide wafer 15 by clamping or adsorption. The mask plate 12 is arranged on the side of the stage 11 that carries the silicon carbide wafer 15, and the mask plate 12 includes an opening 121. Exemplarily, the opening 121 can be rectangular, and the orthographic projection of the opening 121 on the stage 11 is at least partially located within the range of the orthographic projection of the silicon carbide wafer 15 on the stage 11, that is, the area of ​​the projection of the opening 121 on the stage 11 is less than or equal to the area of ​​the projection of the silicon carbide wafer 15 on the stage 11. The moving device 13 is used to control the relative movement between the mask plate 12 and the carrier 11 . The ion implantation device 14 is disposed on a side of the mask plate 12 away from the carrier 11 . The ion implantation device 14 is used to implant ions into the silicon carbide wafer 15 through the opening 121 of the mask plate 12 .

[0036] Exemplarily, the surface of the carrier 11 is parallel to the plane XY. After the sample preparation device 1 is started, the moving device 13 controls the mask plate 12 and the silicon carbide wafer 15 to move relative to each other. When the opening 121 is aligned with the preset sample preparation area 150 of the silicon carbide wafer 15, the mask plate 12 and the carrier 11 move relatively still to the position for ion implantation, and then the ion implantation device 14 is controlled to inject ions into the silicon carbide wafer 15 through the opening 121 of the mask plate 12 to form the sample preparation area 150. Since the moving device 13 can control the relative movement of the mask plate 12, the carrier 11 and the silicon carbide wafer 15, the ion implantation area of ​​the silicon carbide wafer 15 can be adjusted by adjusting the relative position of the mask plate 12 and the silicon carbide wafer 15 to form multiple sample preparation areas 150 on the silicon carbide wafer 15. Compared to the above, Figure 1 In the sample preparation process shown, the sample preparation device 1 proposed in the embodiment of the present application is simpler to operate, has a shorter sample preparation cycle, and has a lower sample preparation cost.

[0037] Figure 3 Another structural schematic diagram of the sample preparation device provided in an embodiment of the present application.

[0038] In some embodiments, Figure 3 As shown, the moving device 13 includes a first moving device 131 and a second moving device 132. The first moving device 131 is connected to the mask plate 12 and is used to control the mask plate 12 to move in a direction parallel to the carrier 11, so that the mask plate 12 moves relative to the carrier 11. The second moving device 132 is connected to the carrier 11 and is used to control the carrier 11 and the silicon carbide wafer 15 to move in a direction parallel to the mask plate 12, so that the carrier 11 and the silicon carbide wafer 15 move relative to the mask plate 12. Exemplarily, the surfaces of the carrier 11 and the mask plate 12 are both parallel to the XY plane. During the alignment process of the carrier 11 and the opening 121 on the mask plate 12, the movement of the mask plate 12 can be controlled by only the first moving device 131, or by only the second moving device 132. The mask plate 12 can also be controlled by the first moving device 131, and the carrier 11 can be controlled by the second moving device 132, so that the mask plate 12 and the carrier 11 produce relative movement in a direction parallel to the XY plane. After the alignment is completed, the first moving device 131 and the second moving device 132 respectively control the mask plate 12 and the carrier 11, so that the two move relatively still to the position for ion implantation, and then the ion implantation device 14 injects ions into the silicon carbide wafer 15 through the opening 121 of the mask plate 12 to form a sample preparation area 150.

[0039] In some embodiments, Figure 3As shown, the silicon carbide wafer 15 may include one or more sample preparation regions 150 . When the silicon carbide wafer 15 includes multiple sample preparation regions 150 , at least two sample preparation regions 150 have different ion implantation parameters.

[0040] Exemplarily, the first moving device 131 can control the mask plate 12 to continue to move so that the projection of the opening 121 on the silicon carbide wafer 15 along the direction Z falls on an area other than the sample preparation area 150. By adjusting various parameters of the ion implantation device 14, such as the implantation dose, the implantation depth, the implantation ion type and other parameters, multiple sample preparation areas can be obtained, thereby improving the utilization rate of the silicon carbide wafer 15 sample preparation and effectively reducing the sample preparation cost.

[0041] In some embodiments, Figure 3 As shown, the area of ​​the orthographic projection of the opening 121 of the mask plate 12 on the stage 11 is smaller than the area of ​​the orthographic projection of the silicon carbide wafer 15 on the stage 11, and is greater than or equal to the area of ​​the orthographic projection of the sample preparation area 150 on the stage 11. The area of ​​the orthographic projection of the opening 121 on the stage 11 is greater than or equal to the area of ​​the orthographic projection of the sample preparation area 150 on the stage 11, which provides a certain margin for the range of ion implantation on the silicon carbide wafer 15, so that the boundary of the sample preparation area 150 is completely implanted, and the accuracy of the sample analysis results is improved in the subsequent analysis process of the sample.

[0042] Figure 4 A diagram of the opening shape on the mask plate provided in an embodiment of the present application.

[0043] In some embodiments, Figure 4 As shown in FIG. 1 , the shape of the orthographic projection of the opening 121 of the mask plate 12 on the carrier 11 is a rectangle, a square, a circle or a sector. For example, when the mask plate 12 is parallel to the carrier 11, the shape of the opening 121 on the mask plate 12 can be as follows: Figure 3 As shown, it is a rectangle, or it can be Figure 4 As shown, it is one of square, circular or sector-shaped. The shapes of various openings 121 can better meet the shape requirements of the sample preparation area 150.

[0044] In some embodiments, Figure 4 As shown, the shape of the orthographic projection of the opening 121 of the mask plate 12 on the stage 11 is a square, and the side length of the square is greater than or equal to 8 mm.

[0045] Figure 5 Schematic diagram of the sample preparation area of ​​the silicon carbide wafer in an embodiment of the present application.

[0046] For example, Figure 5As shown, taking the diameter of the silicon carbide wafer 15 as 200 mm and the side length of a square sample preparation area 150 as 8 mm as an example, theoretically, the number of sample preparation areas 150 that can be prepared on a silicon carbide wafer 15 is N=3.14×100 2 / (8×8)≈490, the number of sample preparation areas 150 on each silicon carbide wafer 15 is greatly increased.

[0047] The embodiment of the present application also provides a wafer sample preparation method, Figure 6 A flow chart of the sample preparation method provided in the embodiment of the present application, Figure 7 to Figure 10 for Figure 6 The diagrams of the steps in the Figure 6 As shown, the preparation method includes the following steps S1 to S4:

[0048] Step S1: Figure 7 As shown, the silicon carbide wafer 15 is placed on the carrier 11, and the carrier 11 can fix the silicon carbide wafer 15 by clamping or adsorption.

[0049] Step S2: Figure 8 As shown, the mask plate 12 is disposed on the side of the carrier 11 that carries the silicon carbide wafer 15, and the mask plate 12 includes an opening 121, and the orthographic projection of the opening 121 on the carrier 11 is at least partially located within the range of the orthographic projection of the silicon carbide wafer 15 on the carrier 11, that is, the area of ​​the projection of the opening 121 on the carrier 11 is less than or equal to the area of ​​the projection of the silicon carbide wafer 15 on the carrier 11. Exemplarily, the shape of the orthographic projection of the opening 121 of the mask plate 12 on the carrier 11 can be one of a rectangle, a square, a circle, or a sector.

[0050] In some embodiments, the mask plate 12 is disposed on the side of the carrier 11 that supports the silicon carbide wafer 15 . Specifically, the mask plate 12 is controlled to move in a direction parallel to the carrier 11 so that the mask plate 12 is located on the side of the carrier 11 that supports the silicon carbide wafer 15 .

[0051] Step S3: Fig. 9 As shown, the mask plate 12 and the stage 11 are controlled to move relative to each other for the first time, so that the orthographic projection of the opening 121 on the mask plate 12 on the stage 11 is located in the preset first sample preparation area 151, so as to realize the alignment of the preset first sample preparation area 151 and the opening 121.

[0052] In some embodiments, controlling the mask plate 12 and the stage 11 to perform a first relative movement specifically includes controlling the mask plate 12 to perform a first movement in a direction parallel to the stage 11, or controlling the stage 11 to perform a first movement in a direction parallel to the mask plate 12, or controlling the mask plate 12 to perform a first movement in a direction parallel to the stage 11, and controlling the stage 11 to perform a first movement in a direction parallel to the mask plate 12, so that the projection of the opening 121 on the mask plate 12 on the stage 11 falls within the silicon carbide wafer 15, that is, falls within the preset first sample preparation area 151.

[0053] Step S4: Fig.10 As shown, after the first alignment is completed, the mask plate 12 and the carrier 11 are controlled to move relatively still to the position for ion implantation, and then the ion implantation device 14 performs the first ion implantation into the silicon carbide wafer 15 through the opening 121 of the mask plate 12 to form a first sample preparation area 151.

[0054] The above-mentioned sample preparation method controls the mask plate 12 and the carrier 11 to perform the first relative movement, so that the opening 121 on the mask plate 12 is aligned with the preset first sample preparation area 151 of the silicon carbide wafer 15, and then the ion implantation device 14 implants ions into the silicon carbide wafer 15 through the opening 121 of the mask plate 12 to form the first sample preparation area 151. By controlling any one or both of the mask plate 12 and the carrier 11 and adjusting the relative position of the mask plate 12 and the silicon carbide wafer 15, the control of the ion implantation area of ​​the silicon carbide wafer 15, that is, the control of the first sample preparation area 151, can be achieved. Compared with the existing sample preparation method, the sample preparation method provided in the embodiment of the present application is simpler to operate and has a shorter sample preparation cycle.

[0055] Fig.11 for Figure 6 The flow chart of steps after step S4 of the sample preparation method shown in FIG. Figure 12-13 for Fig.11 The steps in the diagram.

[0056] In some embodiments, after the first ion implantation in step S4, Figure 7 As shown, the sample preparation method further includes the following steps S5 to S6:

[0057] Step S5: Fig.12As shown, controlling the mask plate 12 and the stage 11 to move relative to each other for the second time can be understood as controlling the mask plate 12 to move for the second time in a direction parallel to the stage 11, or controlling the stage 11 to move for the second time in a direction parallel to the mask plate 12, or controlling the mask plate 12 to move for the second time in a direction parallel to the stage 11, and controlling the stage 11 to move for the second time in a direction parallel to the mask plate 12, so that the orthographic projection of the opening 121 on the mask plate 12 on the stage 11 is located in the preset second sample preparation area 152. The orthographic projection of the preset second sample preparation area 152 on the stage 12 does not overlap with the orthographic projection of the first sample preparation area 151 on the stage 11, so as to achieve the alignment of the preset second sample preparation area 152 and the opening 121.

[0058] Step S6: Fig.13 As shown, after the second alignment is completed, the mask plate 12 and the carrier 11 are controlled to move relatively still to the position for ion implantation, and then the ion implantation parameters of the ion implantation device 14 are adjusted. The ion implantation device 14 is used again to perform a second ion implantation into the silicon carbide wafer 15 through the opening 121 of the mask plate 12 to form a second sample preparation area 152. The ion implantation parameters of the second sample preparation area 152 are different from those of the first sample preparation area 151. The above-mentioned ion implantation parameters include implantation dose, implantation depth, implantation ion type, etc.

[0059] In some embodiments, the above steps S5 to S6 may be repeated to continuously form a third sample preparation area, a fourth sample preparation area, ... an Nth sample preparation area.

[0060] The sample preparation method provided in the embodiment of the present application can obtain multiple sample preparation areas with different ion implantation parameters from a silicon carbide wafer 15, thereby reducing the manufacturing cost of the sample and shortening the sample preparation cycle, making the sample preparation process simpler and more flexible.

[0061] In some embodiments, a sample is obtained by cutting the first sample preparation area 151 obtained by the above-mentioned sample preparation method, and the sample is subjected to SIMS analysis to obtain data such as the concentration and depth of doped ions in the first sample preparation area 151, so as to determine whether the silicon carbide wafer 15 meets the standards for preparing semiconductor devices.

[0062] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A wafer sample preparation device, characterized in that: include: A carrier, used for carrying a silicon carbide wafer; A mask plate is arranged on a side of the carrier that carries the silicon carbide wafer, the mask plate comprises an opening, and an orthographic projection of the opening on the carrier is at least partially located within the range of an orthographic projection of the silicon carbide wafer on the carrier; A moving device, used for controlling the relative movement of the mask plate and the stage; An ion implantation device is arranged on a side of the mask plate away from the carrier, and is used for implanting ions into the silicon carbide wafer through the opening of the mask plate.

2. The sample preparation device according to claim 1, characterized in that: The silicon carbide wafer comprises a plurality of sample preparation areas, and at least two sample preparation areas have different ion implantation parameters; The area of ​​the orthographic projection of the opening of the mask plate on the stage is smaller than the area of ​​the orthographic projection of the silicon carbide wafer on the stage, and is greater than or equal to the area of ​​the orthographic projection of the sample preparation area on the stage.

3. The sample preparation device according to claim 1, characterized in that: The shape of the orthographic projection of the opening of the mask plate on the carrier is one of a rectangle, a square, a circle or a sector.

4. The sample preparation device according to claim 1, characterized in that: The orthographic projection of the opening of the mask plate on the stage is in the shape of a square, and the side length of the square is greater than or equal to 8 mm.

5. The sample preparation device according to claim 1, characterized in that: The moving device includes a first moving device and a second moving device, the first moving device is connected to the mask plate, and the first moving device is used to control the mask plate to move in a direction parallel to the stage, so that the mask plate moves relative to the stage; The second moving device is connected to the carrier, and is used to control the carrier and the silicon carbide wafer to move in a direction parallel to the mask plate, so that the carrier and the silicon carbide wafer move relative to the mask plate.

6. A method for preparing a wafer sample, characterized in that: include: placing a silicon carbide wafer on a stage; Disposing a mask plate on a side of the carrier that supports the silicon carbide wafer, the mask plate comprising an opening, the orthographic projection of the opening on the carrier being at least partially located within the range of the orthographic projection of the silicon carbide wafer on the carrier; Controlling the mask plate and the stage to perform a first relative movement; A first ion implantation is performed into the silicon carbide wafer through the opening of the mask plate to form a first sample preparation area.

7. The sample preparation method according to claim 6, characterized in that: Controlling the mask plate and the stage to perform a first relative movement, comprising: The mask plate is controlled to move for the first time in a direction parallel to the stage, and / or the stage is controlled to move for the first time in a direction parallel to the mask plate.

8. The sample preparation method according to claim 6, characterized in that: After the first ion implantation, the sample preparation method further comprises: Controlling the mask plate and the stage to perform a second relative movement; A second ion implantation is performed into the silicon carbide wafer through the opening of the mask plate to form a second sample preparation area; the orthographic projection of the second sample preparation area on the stage does not overlap with the orthographic projection of the first sample preparation area on the stage, and the ion implantation parameters of the second sample preparation area are different from those of the first sample preparation area.

9. The sample preparation method according to claim 6, characterized in that: The step of arranging the mask plate on a side of the carrier that supports the silicon carbide wafer comprises: The mask plate is controlled to move in a direction parallel to the carrier, so that the mask plate is located at a side of the carrier that supports the silicon carbide wafer.

10. The sample preparation method according to any one of claims 6 to 9, characterized in that: The first sample preparation area is analyzed.

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