Device for improving uniformity of amorphous silicon film

Abstract

The utility model relates to a device for improving the uniformity of an amorphous silicon film, which comprises a reaction chamber, a cabin door arranged on the side surface of the reaction chamber, an observation plate arranged in the center of the cabin door, a gas connecting part arranged in the center of the upper wall of the reaction chamber, a gas phase transmission channel connected above the gas connecting part, and a gas phase diffuser connected with the lower end of the gas connecting part, exhaust pipes are arranged at the two ends of the side wall of the reaction chamber, an electric cylinder is arranged in the center of the lower wall of the reaction chamber, and the upper end of the electric cylinder is connected with a lower polar plate. Through the arrangement of the electric cylinder, the height of the lower polar plate can be controlled, and the non-uniformity of the airflow speed near the substrate is avoided; by adjusting the number of the gas uniformizing through holes at the position of the upper cathode, the gas uniformizing through holes are densely arranged at the central part of the gas distribution plate and are evacuated at the edge part of the gas distribution plate, so that gas is converged at the middle position and is diffused from the middle position to the periphery, the gas flow at the edge is reduced, and the uniformity of a deposited film is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of vacuum coating, in particular to a device for improving the uniformity of amorphous silicon thin films. Background Art

[0002] Solar cells are energy-saving devices that use solar radiation to directly convert into electrical energy. They have the advantages of high energy efficiency, low maintenance cost, and high power stability. They are a greener and more sustainable power generation technology. In the preparation of solar cells, parallel plate capacitor PECVD (plasma enhanced chemical vapor deposition) equipment is a widely used deposition equipment. It uses heating, plasma excitation or light radiation to make gaseous chemicals react and deposit on the wafer surface to form a solid film.

[0003] However, on existing PECVD equipment, the vent holes of the cathode heating plate are evenly arranged, and the exhaust positions are on both sides of the chamber. Such an arrangement will increase the gas flow at the edge, causing the deposited film thickness at the edge to be thicker than that in the center and have poor uniformity. Utility Model Content

[0004] In view of the existing problems, the utility model provides a device for improving the uniformity of amorphous silicon thin film, aiming to solve the problem mentioned in the background technology that the gas flow at the edge position increases, resulting in the thickness of the deposited film at the edge position being thicker than that at the center and having poor uniformity.

[0005] In order to solve the above problems, the utility model provides a device for improving the uniformity of amorphous silicon thin film, including a reaction chamber, a hatch is arranged on the side of the reaction chamber, an observation plate is arranged in the center of the hatch, a gas connection part is arranged on the upper part of the reaction chamber, a gas transmission channel passing through the upper wall of the reaction chamber is connected to the upper part of the gas connection part, an intake valve is connected to the gas transmission channel on the upper side of the top of the reaction chamber, a gas diffuser is connected to the lower end of the gas connection part, a gas distribution plate is installed at the lower end of the gas diffuser, two exhaust pipes are symmetrically arranged on the side wall of the reaction chamber, an electric cylinder is arranged in the center of the lower wall of the reaction chamber, and a lower electrode plate is connected to the upper end of the electric cylinder.

[0006] Furthermore, the air distribution plate is provided with air uniformity holes.

[0007] Furthermore, the air uniforming holes are densely arranged in the central part of the air distribution plate and sparsely arranged in the edge part of the air distribution plate.

[0008] Furthermore, a baffle is provided at the connection between the gas connection part and the gas phase diffuser.

[0009] Furthermore, the baffle includes a baffle body, and a plurality of hanging ears are arranged on the outer side of the baffle body. The hanging ears are L-shaped and have fixing through holes at the upper ends.

[0010] Furthermore, the other end of the hanging ear is fixed to the upper wall of the gas phase diffuser through a fixing through hole.

[0011] Furthermore, the other end of the gas phase transmission channel is connected to a plasma source, and the other end of the exhaust pipe is connected to an exhaust device.

[0012] Compared with the prior art, the utility model has the following beneficial effects:

[0013] 1. The utility model adjusts the number of uniform gas holes at the upper cathode position. The uniform gas holes are densely arranged in the central part of the gas distribution plate and sparsely arranged at the edge of the gas distribution plate, so that the gas converges in the middle position and diffuses from the middle position to the surroundings, reducing the gas flow at the edge, thereby improving uniformity.

[0014] 2. The utility model can control the height of the lower electrode plate by setting an electric cylinder, thereby avoiding the problem of uneven air flow velocity near the substrate, which in turn affects the uniformity of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The overall structure diagram of a device for improving the uniformity of an amorphous silicon thin film is shown;

[0016] Figure 2 A schematic diagram of the cross-sectional structure of a device for improving the uniformity of an amorphous silicon thin film;

[0017] Figure 3 A schematic diagram of the gas distribution part of a device for improving the uniformity of an amorphous silicon thin film;

[0018] Figure 4 A schematic diagram of a gas distribution plate portion of a device for improving uniformity of an amorphous silicon thin film;

[0019] Figure 5 A schematic diagram of a baffle portion of a device for improving uniformity of an amorphous silicon thin film;

[0020] Description of the numbers in the figure:

[0021] 1. Reaction chamber; 2. Gas transmission channel; 3. Inlet valve; 4. Gas connection part; 5. Gas diffuser; 6. Gas distribution plate; 601. Gas uniformity hole; 7. Vacuum pipe; 8. Electric cylinder; 9. Lower electrode plate; 10. Base material; 11. Baffle; 1101. Baffle body; 1102. Hanging ear; 1103. Fixing hole; 12. Hatch door; 13. Observation plate. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] See also Figure 1-Figure 5 The utility model provides a device for improving the uniformity of amorphous silicon thin film, comprising a reaction chamber 1, a hatch 12 is arranged on the side of the reaction chamber 1, an observation plate 13 is arranged in the center of the hatch 12, a gas connection part 4 is arranged on the upper part of the reaction chamber 1, a gas transmission channel 2 passing through the upper wall of the reaction chamber 1 is connected to the upper part of the gas connection part 4, an intake valve 3 is connected to the gas transmission channel 2 located on the upper side of the top of the reaction chamber 1, a gas diffuser 5 is connected to the lower end of the gas connection part 4, a gas distribution plate 6 is installed at the lower end of the gas diffuser 5, two exhaust pipes 7 are symmetrically arranged on the side wall of the reaction chamber 1, an electric cylinder 8 is arranged in the center of the lower wall of the reaction chamber 1, and a lower electrode plate 9 is connected to the upper end of the electric cylinder 8.

[0024] Wherein, the air distribution plate 6 is provided with air uniformity holes 601 .

[0025] The air uniforming holes 601 are densely arranged in the central part of the air distribution plate 6 and sparsely arranged in the edge part of the air distribution plate 6 .

[0026] Wherein, a baffle 11 is provided at the connection between the gas connection part 4 and the gas phase diffuser 5 .

[0027] The baffle 11 includes a baffle body 1101 , and a plurality of hanging ears 1102 are arranged on the outer side of the baffle body 1101 . The hanging ears 1102 are L-shaped, and a fixing through hole 1103 is opened at the upper end.

[0028] The other end of the hanging ear 1102 is fixed to the upper wall of the gas phase diffuser 5 through a fixing through hole 1103 .

[0029] The other end of the gas phase transmission channel 2 is connected to a plasma source, and the other end of the exhaust pipe 7 is connected to an exhaust device.

[0030] Among them, the plasma source and the exhaust equipment are both existing technologies and will not be described in detail here.

[0031] Specific embodiments of the utility model:

[0032] When working, the substrate 10 is placed on the lower electrode plate 9, the vertical position of the substrate 10 is adjusted by the electric cylinder 8, the exhaust device is started, the reaction chamber 1 is evacuated to a vacuum state through the exhaust pipe 7, the air inlet valve 3 is opened, and the high-temperature plasma flows from the plasma source through the gas phase transmission channel 2 to the gas connection part 4, and then enters the gas phase diffuser 5. After the plasma is buffered by the baffle 11, it contacts the gas distribution plate 6 through the space between the hanging ears 1102, and enters the reaction chamber 1 through the uniform gas through hole 601. The reaction substances in the gas phase will be deposited on the surface of the substrate to form a thin film; after the deposition is completed, the residual gas is discharged from the reaction chamber through the exhaust pipe 7, and the substrate 10 is cooled at the same time to prevent the film from being ruptured by thermal stress. If necessary, the deposited film can also be subjected to subsequent treatment, such as annealing, oxidation, etc., to change its properties and surface characteristics.

[0033] Among them, the uniform gas holes 601 on the gas distribution plate 6 are densely arranged in the central part of the gas distribution plate 6 and sparsely arranged at the edge part of the gas distribution plate 6, so that the plasma converges in the middle position and diffuses from the middle position to the surroundings, avoiding the problem of excessive gas flow at the edge position causing the thickness of the deposited film at the edge to be thicker than that in the center.

[0034] The baffle 11 prevents the gas distribution plate 6 from directly contacting the high-temperature plasma, which would cause thermal deformation of the gas distribution plate 6 and poor coating uniformity, thereby extending the service life and reducing the frequency of repair and maintenance.

[0035] Among them, when the distance between the upper and lower plates is too small, strong eddies will be generated in the airflow field near the substrate, affecting the uniformity of the deposited film. When the distance between the upper and lower plates is too large, the formation and movement of the plasma will be restricted, resulting in insufficient energy of the plasma, which will also affect the uniformity of the deposited film. The uniformity is optimal when the distance between the upper and lower plates is 20 mm.

[0036] The above is only a preferred specific implementation of the utility model; however, the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and improved ideas of the utility model within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model.

Claims

1. A device for improving the uniformity of an amorphous silicon thin film, comprising a reaction chamber (1), a hatch (12) being arranged on the side of the reaction chamber (1), and an observation plate (13) being arranged in the center of the hatch (12), characterized in that: A gas connection portion (4) is provided at the top of the reaction chamber (1), and a gas phase transmission channel (2) passing through the upper wall of the reaction chamber (1) is connected to the top of the gas connection portion (4). An intake valve (3) is connected to the gas phase transmission channel (2) located on the upper side of the top of the reaction chamber (1). A gas phase diffuser (5) is connected to the lower end of the gas connection portion (4), and a gas distribution plate (6) is installed at the lower end of the gas phase diffuser (5). Two exhaust pipes (7) are symmetrically provided on the side wall of the reaction chamber (1). An electric cylinder (8) is provided in the center of the lower wall of the reaction chamber (1), and a lower electrode plate (9) is connected to the upper end of the electric cylinder (8).

2. The device for improving uniformity of an amorphous silicon thin film according to claim 1, characterized in that: The air distribution plate (6) is provided with air uniformity holes (601).

3. The device for improving uniformity of an amorphous silicon thin film according to claim 2, characterized in that: The air uniforming holes (601) are densely arranged in the central part of the air distribution plate (6) and sparsely arranged in the edge part of the air distribution plate (6).

4. The device for improving uniformity of amorphous silicon thin film according to claim 1, characterized in that: A baffle (11) is provided at the connection between the gas connection portion (4) and the gas phase diffuser (5).

5. The device for improving uniformity of amorphous silicon thin film according to claim 4, characterized in that: The baffle (11) comprises a baffle body (1101), a plurality of hanging ears (1102) are arranged on the outside of the baffle body (1101), the hanging ears (1102) are L-shaped, and a fixing through hole (1103) is opened at the upper end.

6. The device for improving uniformity of amorphous silicon thin film according to claim 5, characterized in that: The other end of the hanging ear (1102) is fixed to the upper wall of the gas phase diffuser (5) through a fixing through hole (1103).

7. The device for improving uniformity of amorphous silicon thin film according to claim 1, characterized in that: The other end of the gas phase transmission channel (2) is connected to a plasma source, and the other end of the exhaust pipe (7) is connected to an exhaust device.

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