Wafer pickling tank
By designing the main body and cross-shaped partition structure of the wafer pickling tank, the problem that existing pickling tanks can only etch wafers of a single size specification was solved, realizing uniform etching of wafers of different sizes and improving the accuracy of Hall effect testing.
Patent Information
- Application Number
- CN202422973275.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-03
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-12-03
AI Technical Summary
Existing pickling tanks can only corrode square wafers of a single size, resulting in uneven corrosion and air bubbles affecting the accuracy of Hall effect test results.
A wafer pickling tank was designed, comprising a main body and a first cross-shaped partition. The main body has grooves and through holes, which can horizontally place wafers of different sizes and specifications, increase the contact area, and quickly remove air bubbles, ensuring comprehensive etching of the four corners.
Uniform etching of wafers of different sizes and specifications was achieved, improving etching efficiency and the accuracy of Hall effect testing.
Smart Images
Figure CN223616355U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of crystal preparation, and more specifically to a wafer pickling tank. Background Technology
[0002] Before producing indium antimonide single crystals, the polycrystalline material needs to be screened to obtain single crystals with higher performance. Hall effect testing is typically used to select polycrystalline materials with acceptable carrier concentration and electron mobility. Hall effect testing requires etched and cleaned square indium antimonide wafers. In existing technology, a pickling tank with densely spaced grids (wafers placed vertically) is used for etching. However, this type of pickling tank has the following disadvantages:
[0003] It is only applicable to square wafers with a side length of 10mm, and cannot be used for square wafers with a side length of 20mm;
[0004] The etching solution currently used generates a large amount of gas during the etching process. Because the spacing between the barriers is too small, these bubbles easily adhere to the wafer surface, preventing the reaction from continuing and resulting in uneven etching of the wafer surface, which in turn affects the accuracy of the Hall effect test results. Utility Model Content
[0005] In view of the problems existing in the prior art, one object of this disclosure is to provide a wafer pickling tank that can overcome the limitation of pickling tanks in the prior art that can only etch square wafers of a single size.
[0006] Another objective of this disclosure is to provide a wafer pickling tank that can increase the contact area between the wafer surface and the etching solution, thereby improving the etching efficiency and etching effect.
[0007] Another object of this disclosure is to provide a wafer pickling tank that allows bubbles generated by the reaction between the wafer and the etching solution to be easily and quickly discharged.
[0008] Another objective of this disclosure is to provide a wafer pickling tank that enables the four corners of the wafer to be accurately and comprehensively etched, ensuring the reliability of setting electrodes at the four corners during Hall testing.
[0009] Therefore, a wafer pickling tank is provided for placing square wafers for Hall testing and then placing them in a container filled with etching solution to etch the wafers. The wafer pickling tank includes a main body and a first cross partition. The main body has an upper surface and a lower surface opposite to each other along the thickness direction, a peripheral surface connecting the upper surface and the lower surface, and a first groove. The first groove is recessed from the upper surface to a first depth and spaced apart from the lower surface. The projection of the first groove along the thickness direction is square. The first cross partition is located in the first groove. The top surface of the first cross partition is lower than the upper surface of the main body in the thickness direction. The first groove is used to horizontally place large square wafers for Hall testing on the top surface of the first cross partition. The first cross partition divides the first groove into four second grooves. The projection of the second groove along the thickness direction is square. The second groove is used to horizontally place small square wafers for Hall testing within it. The main body has four through holes at the four bottom corners of each second groove. Each through hole penetrates the main body along the thickness direction. The projection of each through hole along the thickness direction is square. Each through hole is used to allow etching solution to flow from the outside of the main body into the second groove and the first groove.
[0010] The beneficial effects of this disclosure are as follows.
[0011] In the wafer pickling tank according to this disclosure, a large-sized square wafer for Hall testing is horizontally placed in a first groove, enabling etching of the large-sized wafer; a small-sized square wafer for Hall testing is horizontally placed within a second groove, enabling etching of the small-sized wafer. With a single first groove, one large-sized wafer can be etched, or four small-sized wafers can be etched simultaneously, thus overcoming the limitation of prior art pickling tanks that can only etch square wafers of a single size.
[0012] In the wafer pickling tank according to this disclosure, whether a large-size wafer is placed in a single first groove or a small-size wafer is placed in each of the second grooves, both the large-size and small-size wafers are placed horizontally. This increases the contact area between the surfaces of the large-size and small-size wafers (collectively referred to as wafers) and the etching solution, thereby improving the etching efficiency and etching effect.
[0013] Furthermore, due to the horizontal placement, when large-size wafers and small-size wafers are not etched simultaneously, each first groove and each second groove contains only one wafer (corresponding to the large-size wafer or the small-size wafer). That is, no other wafers are stacked on top of each wafer in the thickness direction. Compared with the vertical placement of the prior art, the bubbles generated by the reaction between the wafer and the etching solution during the etching process can be easily and quickly discharged without adhering to the surface of the wafer and hindering the reaction between the etching solution and the wafer. This makes the surface etching of the wafer uniform, thereby ensuring the accuracy of the Hall test results.
[0014] In the wafer pickling tank according to this disclosure, the main body has four through holes at the four bottom corners of each of the second grooves. Each through hole penetrates the main body along the thickness direction, and the projection of each through hole along the thickness direction is a square. The four square through holes correspond exactly to the four corners of the small-sized wafer. When the etching solution flows from the outside of the main body into the second groove and reacts with the small-sized wafer, the generated bubbles push the small-sized wafer upwards due to the vigorous etching reaction. The bubbles are discharged from the periphery of the second groove, so the horizontally placed small-sized wafer will not stick to the bottom surface of the second groove. For large-sized wafers, since the large-sized wafer is placed on the top surface of the first cross partition, and there are four second grooves in the first groove, totaling sixteen through holes, the reaction bubbles will also lift the large-sized wafer upwards and remove it from the top surface of the first cross partition. Thus, the part of the large-sized wafer facing the first cross partition will come into contact with the etching solution, and the entire surface of the large-sized wafer facing the first cross partition will come into contact with the etching solution and be etched. Similarly, the bubbles are discharged from the periphery of the first groove. Whether etching small-sized or large-sized wafers, the four corners of the wafer (i.e., small-sized or large-sized wafers) will be accurately and completely etched, thus ensuring the reliability of setting electrodes at the four corners during Hall effect testing. Attached Figure Description
[0015] Figure 1 This is a perspective view of a wafer pickling tank according to the present disclosure, wherein the dashed lines schematically show the container for holding the etching solution, and large-size wafers and small-size wafers are not placed in the wafer pickling tank.
[0016] Figure 2 This is a top view of the wafer pickling tank according to this disclosure.
[0017] Figure 3 yes Figure 1 A three-dimensional schematic diagram of a wafer pickling tank, wherein the dashed lines schematically show the container used to hold the etching solution, and a large-size wafer and a small-size wafer are placed in the wafer pickling tank.
[0018] Figure 4 yes Figure 3 A variation of the above.
[0019] The reference numerals in the attached figures are explained below.
[0020] 100 wafer pickling tank with 16 through holes
[0021] T-thickness direction 2 First cross-shaped partition
[0022] 1. Main body; 3. Second cross partition
[0023] 11. Top surface with 4 handles
[0024] 12 Lower surface 200 container
[0025] 13-sided 300 large-size chip
[0026] 14 First Groove 400 Small Size Chip
[0027] 15 Second Groove Detailed Implementation
[0028] The accompanying drawings illustrate embodiments of this disclosure, and it will be understood that the disclosed embodiments are merely examples of this disclosure, which can be implemented in various forms. Therefore, the specific details disclosed herein should not be construed as limiting, but are intended only as the basis for the claims and as an illustrative basis to teach those skilled in the art how to implement this disclosure in various ways.
[0029] Reference Figures 1 to 4 According to this disclosure, the wafer pickling tank 100 is used to place square wafers for Hall testing, and then place them in a container 200 containing an etching solution to etch the placed wafers.
[0030] The wafer pickling tank 100 includes a main body 1 and a first cross-shaped partition 2. The main body 1 has an upper surface 11 and a lower surface 12 opposite to each other along the thickness direction T, a peripheral surface 13 connecting the upper surface 11 and the lower surface 12, and a first groove 14 recessed downward from the upper surface 11 to a first depth and spaced apart from the lower surface 12. The projection of the first groove 14 along the thickness direction T is square. The first cross-shaped partition 2 is located within the first groove 14. The top surface of the first cross-shaped partition 2 is lower than the upper surface 11 of the main body 1 in the thickness direction T. The first groove 14 is used for horizontally placing a large square wafer 300 for Hall effect testing on the top surface of the first cross-shaped partition 2. The first cross-shaped partition divides the first groove 14 into four second grooves 15. The projection of the second grooves 15 along the thickness direction T is square. The second grooves 15 are used for horizontally placing small square wafers 400 for Hall effect testing within them. The main body 1 has four through holes 16 at the four bottom corners of each of the second grooves 15. Each through hole 16 penetrates the main body 1 along the thickness direction T. The projection of each through hole 16 along the thickness direction T is a square. Each through hole 16 is used to allow the corrosive liquid to flow from the outside of the main body 1 into the second groove 15 and the first groove 14.
[0031] In the wafer pickling tank 100 according to this disclosure, a large-sized square wafer 300 for Hall effect testing is horizontally placed in a first groove 14, enabling etching of the large-sized wafer 300; a small-sized square wafer 400 for Hall effect testing is horizontally placed within a second groove 15, enabling etching of the small-sized wafer 400. With a single first groove 14, one large-sized wafer 300 can be etched, or four small-sized wafers 400 can be etched simultaneously, thus overcoming the limitation of prior art pickling tanks that can only etch square wafers of a single size.
[0032] In the wafer pickling tank 100 according to this disclosure, whether a large-size wafer 300 is placed in a single first groove 14 or a small-size wafer 400 is placed in each of the second grooves 15, the large-size wafer 300 and the small-size wafer 400 are placed horizontally. This increases the contact area between the surface of the large-size wafer 300 and the small-size wafer 400 (collectively referred to as wafers) and the etching solution, thereby improving the etching efficiency and etching effect.
[0033] Furthermore, due to the horizontal placement, when the large-size wafer 300 and the small-size wafer 400 are not etched simultaneously, each first groove 14 and each second groove 15 contains only one wafer (corresponding to the large-size wafer 300 or the small-size wafer 400). That is, no other wafers are stacked on each wafer in the thickness direction T. Compared with the vertical placement in the prior art, the bubbles generated by the reaction between the wafer and the etching solution during the etching process can be easily and quickly discharged without adhering to the surface of the wafer and hindering the reaction between the etching solution and the wafer. This makes the surface etching of the wafer uniform, thereby ensuring the accuracy of the Hall test results.
[0034] In the wafer pickling tank 100 according to the present disclosure, the main body 1 has four through holes 16 at the four bottom corners of each of the second grooves 15. Each through hole 16 penetrates the main body 1 along the thickness direction T. The projection of each through hole 16 along the thickness direction T is a square. The four square through holes 16 correspond exactly to the four corners of the small-sized wafer 400. When the etching solution flows from the outside of the main body 1 into the second groove 15 and reacts with the small-sized wafer 400, because the etching reaction is relatively intense, the generated bubbles push the small-sized wafer 400 upward. The bubbles are discharged from the periphery of the second groove 15. In this way, the horizontally placed small-sized wafer 400 will not stick to the bottom surface of the second groove 15. For the large-size wafer 300, since it is placed on the top surface of the first cross-shaped partition 2, and the first groove 14 contains four second grooves 15, totaling sixteen through holes 16, the reacting bubbles will lift the large-size wafer 300 upwards, detaching it from the top surface of the first cross-shaped partition 2. This allows the portion of the large-size wafer 300 facing the first cross-shaped partition 2 to come into contact with the etching solution, and the entire surface of the large-size wafer 300 will be corroded. Similarly, the bubbles will exit from the periphery of the first groove 14. Whether etching the small-size wafer 400 or the large-size wafer 300, all four corners of the wafer (i.e., the small-size wafer 400 or the large-size wafer 300) will be accurately and completely etched, thus ensuring the reliability of setting electrodes at the four corners during Hall effect testing.
[0035] In the wafer pickling tank 100 according to this disclosure, the first cross-shaped partition 2 and the main body 1 form a positional constraint on each small-sized wafer 400 around the perimeter. When only one first groove 14 is provided (e.g. Figure 4 As shown), the main body 1 forms a positional constraint on the large-size wafer 300 around its perimeter.
[0036] To increase the amount of corrosion and improve corrosion efficiency, in one example, such as Figures 1 to 3As shown, the wafer pickling tank 100 also includes a second cross-shaped partition 3, the top surface of which is higher than the top surface of the first cross-shaped partition 2 in the thickness direction T; there are four first grooves 14, which are separated from each other by the second cross-shaped partition 3. In this way, four large-size wafers 300 can be etched at the same time, or 16 small-size wafers 400 can be etched at the same time.
[0037] like Figure 1 and Figure 3 As shown, in one example, the top surface of the second cross partition 3 is coplanar with the upper surface 11 of the main body 1.
[0038] like Figure 2 and Figure 4 As shown, in one example, the side length of the square projected by the second groove 15 along the thickness direction T is 10 mm; the side length of the small-sized wafer 400 is 10 mm to fit the gap with the second groove 15; and the side length of the large-sized wafer 300 is 20 mm. Of course, the side length of the small-sized wafer 400 can be less than 10 mm, such as 8 mm or 9 mm, as long as the Hall effect test requirements are met.
[0039] like Figure 2 and Figure 4 As shown, in one example, the wall width of the first cross partition 2 is 2 mm.
[0040] Similarly, as Figure 3 As shown, in one example, the wall width of the second cross partition 3 is 2 mm.
[0041] like Figure 2 and Figure 4 As shown, in one example, the side length of the square projected by each through hole 16 along the thickness direction T is 4 mm, thus maximizing the area of each through hole 16.
[0042] In one example, the first depth of the first groove 14 is 8 mm; the height of the first cross partition 2 along the thickness direction T is 4 mm; and the thickness of the main body 1 is 10 mm.
[0043] like Figures 1 to 4 As shown, in one example, the main body 1 is disc-shaped with a diameter of 80 mm. Of course, depending on the volume and size of the container 200, the main body 1 can be a square or rectangle projected along the thickness direction T.
[0044] To facilitate operation by operators, such as Figures 1 to 4 As shown, the wafer pickling tank 100 also includes a handle 4, which extends upward from the upper surface 11 of the main body 1 and is used for the operator's hand to grip. Further, as... Figure 1 and Figure 3As shown, handle 4 is cylindrical. For example, the diameter of the cylinder is 10mm and the length is 150mm.
[0045] In one example, the wafer pickling tank 100 is a single, integrated unit. This means all components of the wafer pickling tank 100 (handle 4, main body 1, first cross partition 2, and even the included second cross partition 3) are integrated, thus increasing the structural strength of the wafer pickling tank 100 and improving the connection strength between the handle 4 and the main body 1, between the main body 1 and the first cross partition 2, and even the included second cross partition 3. Furthermore, the wafer pickling tank 100 is a polytetrafluoroethylene (PTFE) pickling tank. PTFE material has the characteristics of high temperature resistance and acid and alkali resistance, maintaining structural stability in the etching solution and not reacting with the etching solution to contaminate the wafer.
[0046] It should be noted that the wafer pickling tank 100 according to this disclosure is applicable not only to the etching of indium antimonide wafers for Hall testing, but also to the etching of wafers of other materials for Hall testing. Furthermore, the wafer pickling tank 100 according to this disclosure can also be used for etching wafers for other types of tests besides Hall testing.
[0047] Several exemplary embodiments have been described in detail above, but this document is not intended to limit itself to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined to form several other combinations, which are not shown for simplicity.
Claims
1. A wafer etching tank, used for placing square wafers for Hall testing, and then placing them in a container (200) containing an etching solution to etch the wafers, characterized in that, The wafer pickling tank (100) includes a main body (1) and a first cross partition (2); The main body (1) has an upper surface (11) and a lower surface (12) opposite to each other along the thickness direction (T), a circumferential surface (13) connecting the upper surface (11) and the lower surface (12), and a first groove (14). The first groove (14) is recessed into the upper surface (11) to a first depth and is spaced apart from the lower surface (12). The projection of the first groove (14) along the thickness direction (T) is a square. The first cross partition (2) is located in the first groove (14). The top surface of the first cross partition (2) is lower than the upper surface (11) of the main body (1) in the thickness direction (T). The first groove (14) is used to horizontally place the square large-size wafer (300) for Hall test on the top surface of the first cross partition (2). The first cross divides the first groove (14) into four second grooves (15), the projection of the second groove (15) along the thickness direction (T) is square, and the second groove (15) is used to horizontally place the square small-sized specification wafer (400) of the Hall test in it; The main body (1) has four through holes (16) at the four bottom corners of each second groove (15). Each through hole (16) penetrates the main body (1) along the thickness direction (T). The projection of each through hole (16) along the thickness direction (T) is a square. Each through hole (16) is used to allow the corrosive liquid to flow from the outside of the main body (1) into the second groove (15) and the first groove (14).
2. The wafer pickling tank according to claim 1, characterized in that, The wafer pickling tank (100) also includes a second cross partition (3), the top surface of which is higher than the top surface of the first cross partition (2) in the thickness direction (T); There are four first grooves (14), and the four first grooves (14) are separated from each other by the second cross partition (3).
3. The wafer pickling tank according to claim 2, characterized in that, The top surface of the second cross partition (3) is coplanar with the upper surface (11) of the main body (1).
4. The wafer pickling tank according to claim 2, characterized in that, The side length of the square projected by the second groove (15) along the thickness direction (T) is 10mm; The side length of the small-sized wafer (400) is 10mm, which is fitted with the second groove (15) with a gap. The side length of the large-size wafer (300) is 20mm.
5. The wafer pickling tank according to claim 4, characterized in that, The wall width of the first cross partition (2) is 2 mm; and / or The wall width of the second cross partition (3) is 2 mm; and / or The side length of the square projected by each through hole (16) along the thickness direction (T) is 4 mm; and / or The first groove (14) has a first depth of 8 mm, the first cross partition (2) has a height of 4 mm along the thickness direction (T), and the main body (1) has a thickness of 10 mm.
6. The wafer pickling tank according to claim 1, characterized in that, The main body (1) is disc-shaped and has a diameter of 80 mm.
7. The wafer pickling tank according to claim 1, characterized in that, The wafer pickling tank (100) also includes a handle (4). The handle (4) extends upward from the upper surface (11) of the main body (1) and is used for the operator's hand to grip.
8. The wafer pickling tank according to claim 7, characterized in that, The handle (4) is cylindrical and / or The cylinder has a diameter of 10mm and a length of 150mm.
9. The wafer pickling tank according to any one of claims 1-8, characterized in that, The wafer pickling tank is a single, integrated unit.
10. The wafer pickling tank according to claim 9, characterized in that, The wafer pickling tank is a polytetrafluoroethylene acid tank.