Horizontal liquid phase epitaxy graphite boat and method for preventing mother liquid residue

Abstract

This invention discloses a horizontal liquid phase epitaxial graphite boat and method for preventing mother liquor residue, belonging to the field of semiconductor thin film growth technology. The graphite boat mainly includes: a shell, a base plate, a slider, and a movable block. Its key feature is that when the slider slides to the growth position above the substrate, the movable block can seal the mother liquor tank to ensure the growth of the epitaxial film; after growth is completed, the slider continues to slide, moving the movable block together to open the mother liquor tank, allowing the substrate side to be emptied, ensuring that residual mother liquor can be smoothly discharged from the film surface, thereby avoiding mother liquor residue and increasing the usable area of ​​the film.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor thin film growth technology, specifically relating to a horizontal liquid phase epitaxial graphite boat and method for preventing mother liquor residue. Background Technology

[0002] Liquid phase epitaxy (LPE) is a mature semiconductor thin film growth technology. Compared to other epitaxial technologies such as molecular beam epitaxy (MBE), LPE offers advantages such as simple operation, short growth cycle, and fewer defects in epitaxial films obtained through near-thermal equilibrium growth. The main technical approaches to LPE include vertical immersion, horizontal boating, and tilting boating. Compared to other LPE technologies, horizontal LPE offers advantages such as lower mother liquor consumption, higher purity, stable process parameters, and easier thickness control. In horizontal LPE equipment, the graphite boat provides the growth environment for the epitaxial wafer and is the core device for material epitaxial growth. It typically consists of a slider for holding the mother liquor, a base plate for holding the substrate, and a shell. However, for growth systems where the mother liquor has high fluidity at the growth temperature, large areas of mother liquor residue may remain on the film during horizontal LPE. After cooling, this residual mother liquor solidifies on the film surface and is difficult to remove, reducing the yield and usable area of ​​the epitaxial film. To reduce mother liquor residue, the traditional approach is to minimize the gap between the slider and the film surface. However, an excessively small gap can easily cause the slider to scratch the film. Precisely controlling the gap requires maintaining high precision in graphite boat processing, substrate flatness, and epitaxial process technology, which is difficult to achieve consistently in mass production. Summary of the Invention

[0003] In response to the technical problems raised in the background art, the present invention provides a horizontal liquid phase epitaxial graphite boat and method for preventing mother liquor residue. The present invention has a simple structure, is easy to process and use, and can avoid mother liquor residue under large gaps.

[0004] The technical solution of the present invention is as follows:

[0005] A horizontal liquid-phase epitaxial graphite boat for preventing mother liquor residue, comprising:

[0006] Base plate: It has a substrate groove and a movable block groove;

[0007] Slider: Equipped with a mother liquor tank, it can slide along the bottom plate;

[0008] L-shaped movable block: Its lower part is embedded in the movable block groove, and its right side is in close contact with the left side of the substrate groove to form a seal;

[0009] Dynamic drainage mechanism: When the slider slides to the growth position, the movable block seals the mother liquor tank; after the growth is completed, the slider continues to slide and drives the movable block to move, opening the channel between the substrate tank and the movable block tank, so that the residual mother liquor is discharged into the movable block tank by gravity.

[0010] In the above technical solution, the height of the lower part of the movable block is equal to the depth of the movable block groove; the slope on the lower right side of the movable block matches the slope of the movable block groove, forming a leak-free contact surface.

[0011] In the above technical solution, the height of the movable block satisfies the following condition: movable block groove depth < movable block height < movable block groove depth + slider thickness.

[0012] In the above technical solution, the length of the horizontal section on the right side of the movable block is equal to the length of the slider on the left side of the mother liquor tank.

[0013] In the above technical solution, the length of the base plate on the left side of the substrate tank is greater than the length of the movable block plus the length of the mother liquor tank.

[0014] In the above technical solution, the length of the base plate on the right side of the substrate tank is greater than the length of the mother liquor tank.

[0015] In the above technical solution, the length and width of the mother liquor tank are equal to the length and width of the substrate tank, respectively.

[0016] In the above technical solution, the contact surface between the movable block and the slider is a plane, and they slide in conjunction with each other through friction.

[0017] A horizontal liquid phase epitaxy operation method, based on any of the above-mentioned graphite boats, includes the following steps:

[0018] (1) Before growth: The mother liquor tank is located on the right side of the substrate tank, and the movable block seals the substrate tank;

[0019] (2) During growth: The slider moves the mother liquor tank to the top of the substrate tank, and the mother liquor contacts the substrate to perform epitaxy;

[0020] (3) After growth: The slider continues to slide, driving the movable block to move and opening the drainage channel so that the mother liquor flows into the movable block tank.

[0021] In the above technical solution, in step (3), the slider movement distance is greater than or equal to the length of the mother liquor tank, ensuring that the drainage channel is fully open.

[0022] Beneficial effects:

[0023] Compared with other graphite boat designs for reducing mother liquor residue, the advantages of this invention are: the structure is simple, easy to manufacture, easy to implement, and highly reliable; the implementation process is the same as the traditional horizontal boat pushing process, requiring no additional actions. Furthermore, this invention can maintain a significant residual mother liquor removal effect while reducing gap control requirements, simultaneously avoiding scratches and mother liquor residue. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the cross-sectional structure of a graphite boat before growth.

[0025] Figure 2 This is a schematic diagram of the cross-sectional structure of a graphite boat during growth.

[0026] Figure 3 This is a schematic diagram of the cross-sectional structure of the graphite boat after growth.

[0027] In the diagram: 100-base plate, 101-substrate tank, 102-moving block tank, 200-slider, 201-mother liquor tank, 300-moving block. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the following embodiments are only for explaining the present invention, and the scope of protection of the present invention should include all the contents of the claims. Moreover, through the description of the following embodiments, those skilled in the art can fully implement all the contents of the claims of the present invention.

[0029] Example:

[0030] The graphite boat structure for horizontal liquid-phase epitaxial growth provided by this invention is shown in the attached figure. Figure 1 As shown, the system includes: a base plate 100, a slider 200, and a movable block 300. The base plate 100 has a substrate groove 101 for placing the substrate and a movable block groove 102 for placing the movable block. The movable block 300 is L-shaped, with its lower part having the same height as the depth of the movable block groove 102, allowing it to be smoothly embedded into the movable block groove 102 on the base plate 100. The right side of the movable block 300 is tightly fitted against the slope of the movable block groove 102 and in close contact with the left side of the substrate groove 101, ensuring that the mother liquor does not leak during epitaxial growth. The upper height of the movable block 300 needs to ensure that it can slide on the movable block groove 102 of the base plate 100 as the slider 200 moves. Before growth begins, the mother liquor groove 201 is located to the right of the substrate groove 101, as shown below. Figure 1 As shown. At high temperature, the mother liquor in the mother liquor tank 201 melts, and the slider 200 is pulled to... Figure 2 As shown in the growth position, the mother liquor tank 201 is positioned directly above the substrate tank 101 on the base plate 100, with the mother liquor in contact with the substrate, initiating epitaxial growth. After epitaxial growth is complete, as... Figure 3 As shown, the continued movement of slider 200 causes movable block 300 to slide, opening the channel between movable block groove 102 and substrate groove 101. The mother liquor in mother liquor groove 201 flows into movable block groove 102 under the action of gravity.

[0031] In the above embodiment, the lower part of the movable block 300 has the same height as the depth of the movable block groove 102.

[0032] In the above embodiment, the slope on the lower right side of the movable block 300 matches the slope of the movable block groove 102.

[0033] In the above embodiment, the right side of the movable block 300 is in close contact with the left side of the substrate groove 101, forming a sealed space.

[0034] In the above embodiment, the lower inner length of the movable block 300 is the same as the length of the slider 200 to the left of the mother liquor tank 201.

[0035] In the above embodiment, the height of the movable block 300 needs to be greater than the depth of the movable block groove 102, and less than the total height of the movable block groove 102 plus the slider 200.

[0036] In the above embodiment, the length of the base plate 100 to the left of the substrate tank 101 needs to be greater than the total length of the movable block 300 plus the mother liquor tank 201.

[0037] In the above embodiment, the length of the base plate 100 to the right of the substrate tank 101 needs to be greater than the length of the mother liquor tank 201.

[0038] In the above embodiment, the width of the mother liquor tank 201 is the same as the width of the substrate tank 101.

[0039] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A horizontal liquid-phase epitaxial graphite boat for preventing mother liquor residue, characterized in that, include: Base plate: It has a substrate groove and a movable block groove; Slider: Equipped with a mother liquor tank, it can slide along the bottom plate; L-shaped movable block: Its lower part is embedded in the movable block groove. The height of the lower part of the movable block is equal to the depth of the movable block groove. The slope on the lower right side of the movable block matches the slope of the movable block groove to form a leak-free contact surface. The right side is in close contact with the left side of the substrate groove to form a seal. The length of the horizontal section on the right side of the movable block is equal to the length of the slider on the left side of the mother liquor tank. The contact surface between the movable block and the slider is a plane. When sliding, they are linked by friction. Dynamic drainage mechanism: When the slider slides to the growth position, the movable block seals the mother liquor tank; after the growth is completed, the slider continues to slide and drives the movable block to move, opening the channel between the substrate tank and the movable block tank, so that the residual mother liquor is discharged into the movable block tank by gravity.

2. The graphite boat according to claim 1, characterized in that: The height of the movable block must satisfy the following condition: movable block slot depth < movable block height < movable block slot depth + slider thickness.

3. The graphite boat according to claim 1, characterized in that: The length of the base plate on the left side of the substrate tank is greater than the length of the movable block plus the length of the mother liquor tank.

4. The graphite boat according to claim 1, characterized in that: The length of the base plate on the right side of the substrate tank is greater than the length of the mother liquor tank.

5. The graphite boat according to claim 1, characterized in that: The length and width of the mother liquor tank are equal to the length and width of the substrate tank, respectively.

6. A method for horizontal liquid phase epitaxy, based on the graphite boat according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Before growth: The mother liquor tank is located on the right side of the substrate tank, and the movable block seals the substrate tank; (2) During growth: The slider moves the mother liquor tank to the top of the substrate tank, and the mother liquor contacts the substrate to perform epitaxy; (3) After growth: The slider continues to slide, driving the movable block to move and opening the drainage channel so that the mother liquor flows into the movable block tank.

7. The method according to claim 6, characterized in that: In step (3), the slider moves a distance greater than or equal to the length of the mother liquor tank to ensure that the drainage channel is fully open.

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