An apparatus for preparing a surface boron diffusion source layer for mass production of crystalline silicon

Abstract

The application discloses a kind of surface boron diffusion source layer preparation equipment for mass production of crystalline silicon, including pre-evacuation cavity, several coating cavities, vacuum breaking cavity, and the number is several automatic door, load plate driving assembly, pumping system and heating element, pre-evacuation cavity and vacuum breaking cavity are equipped with several coating cavities, each cavity is opened in both sides and is sealedly connected with each other, automatic door is arranged at each cavity connection and the side of pre-evacuation cavity and vacuum breaking cavity, load plate driving assembly is arranged on each cavity for driving load plate moves in cavity, pumping system is used for the vacuum pumping of each sealed cavity, heating element is arranged on coating cavity, vacuum breaking cavity is equipped with gas supply device for inputting protective gas in its interior.The application is oxygen-free in whole process, and the chamber is stainless steel cavity, borosilicate glass is not generated, quartz piece is not damaged, boron source layer preparation rate is fast, effect is good, and large-scale production can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of crystalline silicon solar cells, in particular to a device for preparing a surface boron diffusion source layer for mass production of crystalline silicon. Background Art

[0002] Currently, boron diffusion to form the pn junction is a core process in the manufacture of n-type Topcon crystalline silicon solar cells. This boron diffusion process is currently commonly performed using boron chloride or boron bromide diffusion methods for large-scale production. Both methods suffer from the problem of plating entanglement and are unable to fully resolve it. To address this issue, a method under investigation in recent years involves depositing a boron-containing film on the surface of the silicon wafer using hot-filament CVD or PECVD methods, which serves as a diffusion source layer. The coated silicon wafer is then heated in a furnace to diffuse boron atoms into the wafer, forming the pn junction. However, there is currently no proven mass-production hot-filament CVD equipment suitable for the boron diffusion process. In response to current industrial requirements, we have developed hot-filament CVD equipment suitable for large-scale photovoltaic production, balancing high performance, high production capacity, and cost-effectiveness. Summary of the Invention

[0003] The purpose of the present invention is to solve the above technical problems and to provide a device for preparing a surface boron diffusion source layer for mass production of crystalline silicon.

[0004] The technical solution of the present invention: An equipment for preparing a surface boron diffusion source layer for mass production of crystalline silicon, comprising a pre-vacuum chamber, several coating chambers, a vacuum breaking chamber, and several automatic doors, a carrier driving assembly, an exhaust system and a heating element. Several coating chambers are arranged between the pre-vacuum chamber and the vacuum breaking chamber, and both sides of each chamber are open and sealed to each other. The automatic door is arranged at the connection between each chamber and on one side of the pre-vacuum chamber and the vacuum breaking chamber. The carrier driving assembly is arranged on each chamber for driving the carrier to move in the chamber. The exhaust system is used to vacuum each sealed chamber. The heating element is arranged on the coating chamber. The vacuum breaking chamber is provided with a gas supply device for inputting protective gas into the interior thereof.

[0005] Preferably, one side of the pre-vacuum chamber, the coating chamber and the vacuum breaking chamber are all detachably provided with door panels.

[0006] Preferably, both the pre-vacuum chamber and the vacuum breaking chamber are provided with filling pieces.

[0007] Preferably, each of the cavities is a stainless steel cavity.

[0008] Preferably, a water cooling system is provided outside the coating cavity.

[0009] The beneficial effects of the present invention are: in the present invention, there is no oxygen throughout the entire process, and the chamber is a stainless steel cavity, no borosilicate glass is generated, and the quartz parts will not be damaged. The boron source layer is prepared at a fast rate and with good effect, can be mass-produced, and has a higher cost-effectiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a top view of the overall structure of a preferred embodiment of the present invention;

[0011] Figure 2 Schematic diagram of a pre-vacuum chamber in a preferred embodiment of the present invention;

[0012] Figure 3 Schematic diagram of the coating chamber in a preferred embodiment of the present invention.

[0013] Figure numerals: pre-vacuum chamber 10, coating chamber 2, vacuum breaking chamber 3, automatic door 4, carrier drive assembly 5, exhaust system 6, heating element 7, door panel 8, water cooling system 9. DETAILED DESCRIPTION

[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0015] Reference Figures 1 to 3, an equipment for preparing a surface boron diffusion source layer for mass production of crystalline silicon, comprising a pre-vacuum chamber 10, several coating chambers 2, a vacuum breaking chamber 3, and several automatic doors 4, a carrier driving assembly 5, an exhaust system 6 and a heating element 7. Several coating chambers 2 are arranged between the pre-vacuum chamber 10 and the vacuum breaking chamber 3. Both sides of each chamber are open and sealed to each other. The automatic door 4 is arranged at the connection between each chamber and on one side of the pre-vacuum chamber 10 and the vacuum breaking chamber 3. The carrier driving assembly 5 is arranged on each chamber for driving the carrier to move in the chamber. The exhaust system 6 is used to evacuate each sealed chamber. The heating element 7 is arranged on the coating chamber 2, and the vacuum breaking chamber 3 is provided with a gas supply device for inputting protective gas into it. In the present invention, the automatic door 4 on one side of the pre-vacuum chamber 10 is opened, the carrier with the silicon wafer is placed in the pre-vacuum chamber 10, the automatic door 4 is closed, and the exhaust system 6 extracts the air in the pre-vacuum chamber 10 to make the pre-vacuum chamber 10 in a vacuum state, the automatic door 4 at the connection between the pre-vacuum chamber 10 and the coating chamber 2 is opened, the carrier driving component 5 drives the carrier to move into the coating chamber 2, the automatic door 4 at the connection is closed, and the exhaust system 6 works to extract the air in the coating chamber 2, a boron gas pipe is provided on the coating chamber 2, and the gas with boron element enters from the boron gas pipe, the heating element 7 is energized and generates heat, and the gas undergoes a catalytic decomposition reaction on the heated heating element 7 to produce "uncharged" active groups such as B, which fall on the surface of the crystalline silicon and undergo adhesion, migration, and chemical reactions. Bonding and other reactions are carried out to form a thin film. The automatic door 4 between the coating chambers 2 is opened, and the carrier enters the second coating chamber 2 for coating. Similarly, the crystalline silicon enters several coating chambers 2 for coating to ensure the uniformity of the coating on each crystalline silicon and control the thickness of the coating. When the coating is bent and pressed, the automatic door between the coating chamber 2 and the vacuum breaking chamber 3 is opened, and the carrier carries the crystalline silicon into the vacuum breaking chamber 3. The exhaust system 6 works to extract the air in the vacuum breaking chamber 3, and the gas supply device works to input nitrogen into it to effectively prevent the oxidation of the crystalline silicon. After the entire process is completed, the automatic door 4 on one side of the vacuum breaking chamber 3 is opened, and the crystalline silicon is transported out of the vacuum breaking chamber 3. There is no oxygen in the entire coating process, and the chamber is a stainless steel chamber, no borosilicate glass is generated, and the quartz parts will not be damaged, and the coating efficiency is high.Specifically, the pre-vacuum chamber 10, several coating chambers 2 and the vacuum breaking chamber 3 are all provided with sensors for sensing the carrier plate, and several coating chambers 2 are provided with vacuum sensors, the actions of the automatic door 4, the carrier plate driving assembly 5, the exhaust system 6 and the air supply device and their sequence, the carrier plate and the vacuum sensor detect the pressure value in the chamber through the sensor, and the detected carrier plate signal and the pressure value exceeding the preset value signal are sent to the external control system, and the external control system controls the action, and this control is a conventional technology in the operation of the equipment and will not be described here; the automatic door 4 includes a flap door, a flap shaft and a motor, and the top and bottom sides of the flap door are provided with avoidance grooves to avoid interference with the inner wall of the chamber during rotation, and the flap door is opened up, down and left The right and left sides are both provided with elastic sealing gaskets. The flap door is arranged at the opening of the cavity through the flap shaft. The motor drives the flap shaft to rotate to rotate the flap door, so as to seal or open the openings on both sides of the cavity. The automatic door 4 can also be other existing door structures that can achieve sealing or opening of the cavity opening; the carrier drive assembly 5 includes several motors and gears. Racks are provided on both sides of the upper end of the carrier. The motor drives the gears to rotate and then drives the carrier to move. During the movement, it will abut against another gear, thereby moving the carrier from one cavity to another; the exhaust system 6 includes an exhaust pump and an exhaust pipe, and the exhaust pipe connects the exhaust pump and the cavity; the heating element 7 is a tantalum wire; the air supply device includes two air pipes, nitrogen enters from the air inlet pipe, and flows out from the other air pipe.

[0016] As a preferred embodiment of the present invention, it may also have the following additional technical features:

[0017] In this embodiment, a door panel 8 is detachably provided on one side of the pre-vacuum chamber 10, the coating chamber 2, and the vacuum breaking chamber 3. The door panel 8 can be removed to clean the interior of the chamber. Specifically, the door panel 8 is connected to the chamber wall by bolts.

[0018] In this embodiment, both the pre-vacuum chamber 10 and the vacuum breaking chamber 3 are provided with filling pieces to reduce the internal space of the chamber and shorten the vacuum pumping time.

[0019] In this embodiment, each cavity is a stainless steel cavity.

[0020] In this embodiment, a water cooling system 9 is provided outside the coating cavity 2. Specifically, the water cooling system 9 includes a water pipe and a water pump. The water pipe is provided on the cavity. Water flows in the water pipe, carrying heat and cooling the outside of the cavity.

[0021] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not preclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0022] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An apparatus for preparing a surface boron diffusion source layer for mass production of crystalline silicon, characterized by: The invention comprises a pre-vacuum chamber (10), a plurality of coating chambers (2), a vacuum breaking chamber (3), a plurality of automatic doors (4), a carrier plate driving component (5), an exhaust system (6) and a heating element (7), wherein a plurality of coating chambers (2) are arranged between the pre-vacuum chamber (10) and the vacuum breaking chamber (3), and both sides of each chamber are open and sealed to each other, and the automatic door (4) is arranged at the connection between each chamber and one side of the pre-vacuum chamber (10) and the vacuum breaking chamber (3), and the carrier plate driving component (5) is arranged at the connection between the pre-vacuum chamber (10) and the vacuum breaking chamber (3). 5) is provided on each of the cavities for driving the carrier to move in the cavity, the exhaust system (6) is used to evacuate each sealed cavity, the heating element (7) is provided on the coating cavity (2), the vacuum breaking cavity (3) is provided with a gas supply device for inputting protective gas into the interior thereof, the coating cavity (2) is provided with a boron gas pipe, the boron gas pipe is used to pass gas containing boron element, the heating element (7) catalytically decomposes the gas containing boron element after being energized and heated to generate uncharged active boron groups, and forms a boron diffusion source layer on the surface of the crystalline silicon.

2. The device for preparing a surface boron diffusion source layer for mass production of crystalline silicon according to claim 1, characterized in that: Door panels (8) are detachably provided on one side of the pre-vacuum chamber (10), the coating chamber (2), and the vacuum breaking chamber (3).

3. The device for preparing a surface boron diffusion source layer for mass production of crystalline silicon according to claim 1, characterized in that: Filling pieces are provided in both the pre-vacuum chamber (10) and the vacuum breaking chamber (3).

4. The device for preparing a surface boron diffusion source layer for mass production of crystalline silicon according to claim 1, characterized in that: Each of the cavities is a stainless steel cavity.

5. The device for preparing a surface boron diffusion source layer for mass production of crystalline silicon according to claim 1, characterized in that: A water cooling system (9) is provided outside the coating cavity (2).

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