Chain type equipment for preparing selective emitter

Abstract

The invention discloses chain type equipment for preparing a selective emitter, and the equipment comprises a conveying device for conveying a silicon wafer, and functional areas, namely a chain type texturing area, a first oxidation area, a first deposition area, a drying area, a second oxidation area, a first diffusion area, a second deposition area, a second diffusion area and a third oxidation area, which are sequentially arranged in the conveying direction. The equipment can be used for preparing the selective emitter of the N-type battery, external expansion is controllable, junction depth differentiation is controllable, the texture surface is not damaged, the whole process is chained, and the productivity is high.

Description

technical field [0001] The invention relates to the field of photovoltaics, in particular to a chain device for preparing selective emitters. Background technique [0002] At present, the N-type battery selective emitter preparation process mainly includes: secondary diffusion method, mask method, reverse etching method, laser doping method and doping slurry thermal diffusion method, etc. [0003] The secondary diffusion method needs to go through the steps of depositing mask layer-laser slotting (heavy doping area), first thermal diffusion (preparation of heavy doping area), cleaning mask layer, second thermal diffusion (preparation of light doping area) and other steps , needs to enter and exit the tube furnace twice, and needs to use laser equipment, which is easy to damage the suede structure, takes a long time, costs a lot, and the process is cumbersome. [0004] The masking method needs to go through the first thermal diffusion, mask patterning, BSG cleaning in the no...

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Problems solved by technology

[0003] The secondary diffusion method needs to go through the steps of depositing mask layer-laser slotting (heavy doping area), first thermal diffusion (preparation of heavy doping area), cleaning mask layer, second thermal diffusion (preparation of light doping area) and other steps , needs to enter and exit the tube furnace twice, and needs to use laser equipment, which is easy to damage the suede structure, takes a long time, costs a lot, and the process is cumbersome

[0004] The masking method needs to go through the first thermal diffusion, mask patterning, BSG cleaning in the non-masked area, mask removal, second thermal diffusion and other steps. The whole process also needs to enter and exit the tube furnace twice, which takes a long time. cumbersome operation

[0005] The reverse etching method needs to go through steps such as thermal diffusion, mask patterning, acid etching (non-mask area), and mask layer removal. Although the process steps are simple, the process window is narrow, which is not conducive to process control, and damages the suede surface. Suitable for light-receiving surface structure preparation, and there is environmental protection pressure

[0006] The laser doping method is to perform patterned laser treatment on the surface of the BSG cell after thermal diffusion. There are two difficulties: first, the damage to the suede surface cannot be eliminated by the laser; second, due to the difficulty of boron doping in silicon, the laser Energy control is difficult and the process window is narrow; the contradiction between these two aspects makes the process immature

[0007] In summary, the disadvantages of the existing N-type battery selective emitter preparation process are summarized as follows: ① It takes a long time to enter and exit the tube furnace twice, and the heating and cooling of the tube furnace is time-consuming. The thermal history is too long, which affects the performance of silicon wafers; ②The process is complicated, such as using a mask, it is necessary to deposit a film layer or print a mask, and it is necessary to use a wet method to clean and remove the mask, and the use of chemicals increases the pressure on environmental protection;③ The process is unstable and the window is small, such as laser doping process, the laser energy is too large to damage the front suede structure, the laser energy is too small to do enough boron source, and the expected effect cannot be achieved; ④ damage the suede, and the front of the N-type battery is light-receiving Surface, laser or chemical corrosion will destroy the suede, which has a great impact on the short-circuit current of the battery