Chain-type diffusion technology and chain-type diffusion device

Abstract

The invention provides a chain-type diffusion technology and a chain-type diffusion device, so as to solve the problems that the surface phosphorus concentration of a p-n junction obtained after chain-type diffusion is high and the junction depth is shallow, the surface minority carrier recombination probability is increased, serious electric leakage happens to a junction area, impurities existingin a silicon wafer substrate form a coincidence center easily, and the bulk recombination probability is increased. In the diffusion process of solar cell production, the surface phosphorus concentration of the p-n junction is reduced, the junction depth is increased, surface minority carrier recombination and junction area electric leakage are reduced, the impurities existing in the silicon wafer substrate are absorbed, and the bulk recombination probability is reduced.

Description

Technical field [0001] The invention relates to the technical field of photovoltaic cell production and manufacturing, in particular to a chain diffusion process and chain diffusion equipment. Background technique [0002] At present, the diffusion process in the field of solar cells uses tubular diffusion. The silicon wafer is inserted into the quartz boat, and then put into the quartz tube for impurity diffusion process. The diffusion source is POCl. 3 From a small amount of N 2 Carry into the diffuser tube and pass into O 2 , The two gases react to form P 2 O 5 Deposited on the surface of the silicon wafer, then P 2 O 5 Then react with Si to form P and SiO 2 . In addition, a large amount of N 2 Saturation, prevent impurities from entering, and exclude Cl 2 Wait for exhaust. [0003] Compared with traditional tube diffusion, liquid source chain diffusion adopts H 3 PO 4 , CH 3 CH 2 The mixed solution of OH and deionized water is used as the diffusion source. H 3 PO 4 Easily solu...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is: in order to solve the problems of high phosphorus concentration on the surface of the p-n junction obtained after chain diffusion, shallow junction depth, increased probability of surface minority carrier recombination, serious leakage in the junction region, and the impurity existing in the silicon chip matrix is ​​easy to form. Center, the problem of increased recombination probability in the body, the present invention provides a p-n junction surface phosphorus surface concentration is reduced, the junction depth is increased, the surface minority carrier recombination and the leakage of the junction region are reduced, and impurities in the silicon wafer matrix are absorbed to reduce A Chain Diffusion Process and Chain Diffusion Equipment for Recombination Probability in Vivo

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