Doping method

Abstract

The invention discloses a doping method. The doping method includes the steps a doping layer is formed on a substrate in an ion injection mode; a dielectric layer is formed on the doping layer; annealing processing is carried out on the substrate with the dielectric layer; the dielectric layer is removed through cleaning fluids. After the doping layer is formed through ion injection, the dielectric layer is formed, and accordingly the performance of a PN structure can be improved, the dielectric layer can reduce doping concentration of the surface of the substrate and facilitate repair of lattice defects, the defect density in an injection damage layer can be obviously reduced, impurities on the substrate can be absorbed to a certain extent and accordingly influences of the harmful impurities are reduced.

Description

technical field [0001] The invention relates to a doping method, in particular to a doping method using ion implantation. Background technique [0002] In the current doping process, especially the doping method for making solar cells comprises the following steps: Step S 1 , forming a doped layer on a substrate by means of ion implantation; step S 2 , cleaning the substrate; step S 3 , annealing the substrate. [0003] The disadvantages of this method are: [0004] 1) The implanted damaged layer cannot be well repaired, especially when the lower implanted dose cannot form a completely amorphized damaged layer, thereby deteriorating the performance of the solar cell thus produced. [0005] 2) There is no additional gettering function, which leads to too high requirements on the quality and purity of silicon wafers, and the applicability of the process is not wide. [0006] 3) Implanting the damaged layer In the process of annealing to repair the damage, the implanted la...

AI Technical Summary

Problems solved by technology

[0004] 1) The implanted damaged layer cannot be well repaired, especially when the lower implant dose cannot form a completely amorphized damaged layer, thereby deteriorating the performance of the solar cell thus obtained

[0005] 2) There is no additional gettering function, which leads to too high requirements on the quality and purity of silicon wafers, and the applicability of the process is not wide

Therefore, harmful impurities tend to concentrate in these two regions. Since there is no possibility of subsequent removal of the gettering layer, the performance of solar cells will be further deteriorated in the case of poor quality silicon wafers or pollution introduced by the doping process.

Images