A method for improving the uniformity and stability of the resistance of a diffuser

Abstract

The application discloses a method for improving the uniformity and stability of diffusion resistance, which adopts the furnace tail gas inlet and the furnace mouth gas extraction mode, and the process gas flows from the furnace tail to the furnace mouth; the boat support uniform flow plate and the quartz boat are sequentially placed on the quartz boat support; a plurality of small holes are arranged on the boat support uniform flow plate in sequence; and the furnace inner uniform flow plate is placed at the position close to the gas outlet of the gas inlet pipe at one end of the furnace cavity. The furnace inner uniform flow plate is placed at the position close to the gas outlet of the gas inlet pipe, the process gas is more uniformly dispersed when passing through the furnace inner uniform flow plate, the process gas flow can be more uniformly contacted with the silicon wafer, the influence of the gas flow on the process is avoided, and the uniformity and stability of the diffusion resistance can be greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic cell manufacturing, and particularly relates to a method for improving diffusion sheet resistance uniformity and stability. BACKGROUND

[0002] Solar photovoltaic cells are a new type of cell that directly converts solar light energy into electrical energy. In the preparation process of photovoltaic cells, a boat body for carrying silicon wafers is needed in a process furnace (such as a diffusion furnace or a deposition furnace), and the boat body for carrying silicon wafers is lifted by a push-pull boat to send the silicon wafers into the process furnace. A quartz boat is a commonly used wafer carrying tool. The existing quartz boat adopts a horizontal insertion type wafer placing mode, which is suitable for placing silicon wafers in parallel to the cross-sectional direction of the furnace port. Under the same port diameter condition, the number of silicon wafers placed in this way is low, and the port space cannot be fully utilized. If a vertical insertion type is used, the silicon wafers are placed vertically to the cross-sectional direction of the furnace port, and the support rods of the silicon wafers are arranged on the upper and lower sides of the silicon wafers, so that more silicon wafers can be placed. In the process, the more sufficient the contact between the process gas and the surface of the silicon wafer, the more significant the process effect. Therefore, the quartz boat should be placed as evenly as possible to the process gas flow, and uniform process gas flow is beneficial to improving the diffusion sheet resistance uniformity and stability. SUMMARY

[0003] In view of the above-mentioned defects in the prior art, the present application provides a method for improving diffusion sheet resistance uniformity and stability, so that the process gas flow can be more evenly contacted with the silicon wafers, while avoiding the influence of gas flow on the process, and greatly improving the diffusion sheet resistance uniformity and stability.

[0004] The technical scheme adopted by the present application is as follows:

[0005] A method for improving diffusion sheet resistance uniformity and stability, the gas inlet mode in the process cavity adopts a furnace tail gas inlet and a furnace port gas extraction mode, and the process gas flow is from the furnace tail to the furnace port; a boat support uniform flow plate and a quartz boat are sequentially placed on the boat support; a plurality of small holes are arranged on the boat support uniform flow plate in an orderly and uniform manner; and a furnace uniform flow plate is arranged at a position close to the gas outlet of the gas inlet pipe at one end of the furnace cavity.

[0006] Further improvement of the above technical scheme is as follows:

[0007] The quartz boat support includes a front end plate, a rear end plate, a left side column and a right side column. The front end plate and the rear end plate are located at the two ends of the left side column and the right side column and are connected perpendicularly to the two side columns. A boat support uniform flow plate is arranged at the front end plate and the rear end plate respectively, and the direction of the boat support uniform flow plate is parallel to the front end plate and the rear end plate.

[0008] The boat support uniform flow plate is a single-layer uniform flow plate or a plurality of parallel and spaced uniform flow plates, and the spacing of the plurality of uniform flow plates is 5-30 mm.

[0009] The distance between the boat-holding uniform flow plate and the first quartz boat close to the air inlet end is 80-300mm.

[0010] The furnace uniform flow plate is provided with a plurality of small holes arranged in order and uniformly.

[0011] The shape of the small hole is a round hole, a rhombic hole or a square hole, and the diameter of the round hole is 6-20mm.

[0012] The furnace uniform flow plate is a single-layer circular plate or a plurality of parallel and spaced circular plates, is arranged facing the air outlet direction of the air inlet pipe, and is provided with a plate bracket.

[0013] When the furnace uniform flow plate is a single-layer circular plate, a cylindrical structure with a depth is adopted.

[0014] The quartz boat comprises a left side plate, a right side plate and a plurality of horizontal rods connecting the left side plate and the right side plate, the horizontal rods are divided into upper and lower two rows, the horizontal rods are arranged horizontally or are arranged obliquely to the horizontal direction, the oblique angle θ is 2°-10°, and a continuous clamping groove is arranged on the opposite surfaces of the upper and lower horizontal rods, the clamping groove is a rectangular tooth groove or a ︺-shaped groove with an angle opening to both sides.

[0015] The silicon wafer is placed in a vertical state and is perpendicular to the furnace mouth section, and the air flow penetrates the surface of the silicon wafer.

[0016] The beneficial effects of the present application are as follows:

[0017] The present application is placed with a furnace uniform flow plate close to the air outlet of the air inlet pipe, the gas is more uniformly dispersed when the process gas passes through the furnace uniform flow plate, and the process gas is more uniformly contacted with the silicon wafer. The quartz boat is arranged uniformly, the boat-holding uniform flow plate is arranged on both sides, the distance between the uniform flow plate in the air inlet direction and the side surface of the first quartz boat directly affects the uniformity and stability of the first quartz boat. The process gas first passes through the furnace uniform flow plate, is more uniformly contacted with the silicon wafer after passing through the boat-holding uniform flow plate, and is finally extracted from the process cavity through the uniform flow plate on the other end surface of the boat holder. The process gas flow can be more uniformly contacted with the silicon wafer, the influence of the gas flow on the process is avoided, the diffusion resistance uniformity and stability can be greatly improved. The present application can greatly improve the uniformity and stability of the whole pipe resistance, especially the uniformity and stability of the first quartz boat. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a front view of the quartz boat holder of the present application.

[0019] Figure 2 It is a position diagram of the furnace uniform flow plate of the present application.

[0020] Figure 3 It is a front view of the furnace uniform flow plate of the present application.

[0021] Figure 4 is a rear view. Figure 3

[0022] Figure 5 is a left view. Figure 3

[0023] In the figure: 1, quartz boat holder; 2, boat holder flow uniformizing plate; 3, quartz boat; 4, gas inlet pipe; 5, furnace inner flow uniformizing plate. DETAILED DESCRIPTION

[0024] The specific embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0025] As shown in Figures 1 to 5 , the method for improving the uniformity and stability of the diffusion side resistance of the present application adopts the way of furnace tail gas inlet and furnace mouth gas extraction in the process cavity, and the process gas flows from the furnace tail to the furnace mouth. The boat holder flow uniformizing plate 2 and the quartz boat 3 are placed on the quartz boat holder 1 in sequence, and the quartz boat holder 1 includes a front end plate, a rear end plate, a left side column and a right side column. The front end plate and the rear end plate are located at the two ends of the left side column and the right side column and are connected perpendicularly to the two side columns, forming a rectangular frame. The boat holder flow uniformizing plate 2 is arranged correspondingly at the front end plate and the rear end plate, and is parallel to the direction of the front end plate and the rear end plate, and is horizontally arranged between the left side column and the right side column. A plurality of small holes are arranged on the boat holder flow uniformizing plate 2 in sequence and uniformly. The boat holder flow uniformizing plate 2 is a single-layer flow uniformizing plate or a plurality of parallel and spaced flow uniformizing plates. The spacing between the plurality of flow uniformizing plates is 5-30 mm. The small holes on the adjacent plurality of flow uniformizing plates are completely staggered in the direction of the process gas flow.

[0026] The furnace inner flow uniformizing plate 5 is placed at the position close to the gas outlet of the gas inlet pipe 4 at one end of the furnace cavity, such as at the furnace tail. A plurality of small holes are arranged on the furnace inner flow uniformizing plate 5 in sequence and uniformly. The shape of the small holes is a circular hole, a rhombic hole or a square hole. When the small hole is a circular hole, the diameter is 6-20 mm. The furnace inner flow uniformizing plate 5 is preferably a circular plate, which is arranged in the direction of the gas outlet of the gas inlet pipe 4 and is provided with a plate bracket, and is placed in the furnace cavity through the plate bracket. The furnace inner flow uniformizing plate 5 is a single-layer circular plate or a plurality of parallel and spaced circular plates. When the furnace inner flow uniformizing plate 5 is a single-layer circular plate, a cylindrical structure with a certain depth is adopted.

[0027] A plurality of quartz boats 3 are placed on the inner side of the boat holder flow uniformizing plate 2, and the quartz boats 3 are loaded with silicon wafers. The distance between the boat holder flow uniformizing plate 2 and the first quartz boat 3 close to the gas inlet end is 80-300 mm.

[0028] ​​The quartz boat 3 comprises a left side plate, a right side plate and several horizontal rods connecting the left side plate and the right side plate, the horizontal rods are divided into two rows, comprising a group of upper horizontal rods and a group of lower horizontal rods. The left side plate and the right side plate are vertically arranged, and positioning columns are arranged on the outer sides of the left side plate and the right side plate, the positioning columns are transversely arranged perpendicular to the left side plate and the right side plate, and preferably two positioning columns are arranged on the left side plate and the right side plate.

[0029] As an implementation, the horizontal rods between the left side plate and the right side plate are horizontally arranged. Continuous clamping grooves are arranged on the opposite surfaces of the upper horizontal rods and the lower horizontal rods. The clamping grooves on the horizontal rods are rectangular tooth grooves or V-shaped grooves opening to both sides. The clamping grooves on the upper horizontal rods and the lower horizontal rods correspond to each other and have the same spacing, and clamp the opposite two sides of the silicon wafer respectively. The silicon wafer is placed in a vertical state perpendicular to the furnace port section, and the airflow penetrates through the surface of the silicon wafer. The quartz boat 3 is placed on the quartz boat holder 1 through the left and right positioning columns, and the left side plate and the right side plate are located in the two side columns of the quartz boat holder 1. The number of horizontal rods is preferably four, and the four horizontal rods are parallel to each other to form a cuboid, and the four horizontal rods are respectively located on the four edges of the cuboid. The four horizontal rods are vertically arranged or inclined to the horizontal direction.

[0030] As another implementation, the horizontal rods between the left side plate and the right side plate are inclined to the horizontal direction, and the inclination angle θ is 2°-10°. Continuous clamping grooves are arranged on the opposite surfaces of the upper horizontal rods and the lower horizontal rods. The clamping grooves on the horizontal rods are rectangular tooth grooves or V-shaped grooves opening to both sides. The clamping grooves on the upper horizontal rods and the lower horizontal rods correspond to each other and have the same spacing, and clamp the opposite two sides of the silicon wafer respectively. The silicon wafer is placed in a vertical inclined state perpendicular to the furnace port section, and the airflow penetrates through the surface of the silicon wafer. The quartz boat 3 is placed on the quartz boat holder 1 through the left and right positioning columns, and the left side plate and the right side plate are located in the two side columns of the quartz boat holder 1. The number of horizontal rods is preferably four, and the four horizontal rods are parallel to each other to form a cuboid, and the four horizontal rods are respectively located on the four edges of the cuboid. The four horizontal rods are vertically arranged or inclined to the horizontal direction.

[0031] The above description is an explanation of the present application, not a limitation of the application, and the present application can be modified in any form without departing from the spirit of the present application.

Claims

1. A method of improving the uniformity and stability of spreading resistance, characterized by: The gas inlet mode in the process cavity adopts the mode of furnace tail gas inlet and furnace mouth gas extraction, and the process gas flows from the furnace tail to the furnace mouth; the boat holder uniform flow plate (2) and the quartz boat (3) are sequentially placed on the quartz boat holder (1), the boat holder uniform flow plate (2) is provided with a plurality of small holes arranged in order and uniformly, and the furnace inner uniform flow plate (5) is placed at the position close to the gas outlet of the gas inlet pipe (4) at one end of the furnace cavity; The distance between the boat holder uniform flow plate (2) and the first quartz boat (3) close to the gas inlet end in the gas inlet direction is 80mm-300mm; The silicon wafer is placed in a vertical state and perpendicular to the furnace mouth section, and the airflow penetrates through the surface of the silicon wafer; The quartz boat holder (1) comprises a front end plate, a rear end plate, a left side column and a right side column, the front end plate and the rear end plate are located at the two ends of the left side column and the right side column and are connected perpendicularly to the two side columns, the boat holder uniform flow plate (2) is arranged at the front end plate and the rear end plate respectively, and the boat holder uniform flow plate (2) is parallel to the direction of the front end plate and the rear end plate; The gas sequentially passes through the furnace inner uniform flow plate, the boat holder uniform flow plate close to the gas inlet and the boat holder uniform flow plate on the boat holder away from the gas inlet end.

2. The method of claim 1, wherein: The boat holder uniform flow plate (2) is a single-layer uniform flow plate or a plurality of parallel and spaced uniform flow plates, and the spacing of the plurality of uniform flow plates is 5-30mm.

3. The method of claim 1, wherein: The furnace inner uniform flow plate (5) is provided with a plurality of small holes arranged in order and uniformly.

4. The method of claim 3, wherein the method further comprises: The shape of the small hole is a circular hole, a rhombic hole or a square hole, and when the small hole is a circular hole, the diameter is 6-20mm.

5. The method of claim 1, wherein: The furnace inner uniform flow plate (5) is a single-layer circular plate or a plurality of parallel and spaced circular plates, is arranged in the direction facing the gas outlet of the gas inlet pipe (4), and is provided with a plate bracket.

6. The method of claim 5, wherein the method further comprises: When the furnace inner uniform flow plate (5) is a single-layer circular plate, a cylindrical structure with a depth is adopted.

7. The method of claim 1, wherein: The quartz boat (3) comprises a left side plate, a right side plate and a plurality of horizontal rods connecting the left side plate and the right side plate, the horizontal rods are divided into upper and lower rows, the horizontal rods are arranged horizontally or are arranged inclined to the horizontal direction, the inclination angle θ is 2°-10°; a continuous clamping groove is arranged on the opposite surfaces of the upper horizontal rod and the lower horizontal rod, and the clamping groove is a rectangular tooth groove or a ︺-shaped groove with the opening angle on both sides.

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