Low-pressure diffusion and low-temperature oxidation gettering process

Abstract

The invention provides a low-pressure diffusion and low-temperature oxidation gettering process, and belongs to the field of solar cell gettering processes. The method comprises the steps: low-temperature normal-pressure boat entry, rapid low-pressure heating, high-temperature normal-pressure stabilization, high-temperature low-pressure oxidation, four-step high-temperature low-pressure source communication and knot pushing, long-time cooling, oxidation and impurity absorption, rapid normal-pressure cooling and low-temperature deposition, and low-temperature boat exit. The furnace tube is rapidly cooled for a long time through the steps of cooling, oxidizing and gettering for a long time and controlling the oxygen flow, so that the uniformity and repeatability of diffusion sheet resistanceare improved, the surface doping concentration and junction depth are optimized, the internal defects of a silicon wafer are reduced, and the conversion efficiency of the solar cell is improved.

Description

technical field [0001] The invention relates to a solar cell gettering process, in particular to a novel low-pressure diffusion low-temperature oxidation gettering process. Background technique [0002] Diffusion is a key process in the production process of solar cells. The purpose of diffusion is to make the PN junction of solar cells. The existing solar cell diffusion process mainly includes heating, oxidation, pre-deposition, redistribution, oxidation, and gettering. The process has the advantages of less diffusion time, simple process and easy industrialization, so it has been widely promoted and applied. However, since the P diffusion process of solar cells also includes gettering to the substrate, it is necessary not only to consider forming a better PN junction during P diffusion, but also to consider how to obtain better gettering effects, so as to prepare higher efficient solar cells. Although the currently used diffusion process has a good effect on the prepara...

AI Technical Summary

Problems solved by technology

Although the currently used diffusion process has a good effect on the preparation of PN junctions during P diffusion, the gettering effect on the substrate is not particularly significant.