Quick diffusion annealing method

Abstract

The invention discloses a quick diffusion annealing method. A primary source introduction and pre-deposition process is carried out at below 800 DEG C. After deposition, aerobic heating advance is carried out, and the temperature can rise up to 840-880 DEG C. A PN node advanced at the moment is deep. Then, an aerobic cooling process is carried out, and the temperature drops to 810-850 DEG C. Secondary source introduction is carried out, which is a key step for quick annealing. After that, the furnace door is half-opened immediately, a large amount of nitrogen is introduced, and quick cooling and annealing are carried out. The lattice is repaired to a certain degree, but the phosphorus source still needs certain advance time. Thus, the furnace door is closed slowly, and the temperature goes back to a constant state. The beneficial effects of the method are as follows: through secondary source introduction, the surface concentration is increased, and the filling factor is improved; through lattice repair, thermal damage is reduced, the open-circuit voltage and short-circuit current are improved, and the conversion efficiency of cells is improved; and through quick cooling, the total process time is reduced, the process efficiency is improved, and the production capacity is increased.

Description

technical field [0001] The invention relates to the related technical field of solar cells, in particular to a diffusion rapid annealing method. Background technique [0002] Solar diffusion furnaces mainly include tubular diffusion furnaces and chain diffusion furnaces. The tubular diffusion furnaces include closed-tube diffusion and open-tube diffusion. Since the closed-tube diffusion furnace can be completely isolated from the external environment, it will not be disturbed by the external environment, etc. Advantages, the uniformity of square resistance after diffusion is better, and this equipment is basically used at present. The sealing and heat preservation performance of the closed diffusion furnace is very good, so the ordinary annealing process takes a long time, and the temperature that can be lowered is still high, which is not good for repairing lattice defects, and the extension of the process time will reduce The production output of the cell factory reduces ...

AI Technical Summary

Problems solved by technology

The sealing and heat preservation performance of the closed diffusion furnace is very good, so the ordinary annealing process takes a long time, and the temperature that can be lowered is still high, which is not good for repairing lattice defects, and the extension of the process time will reduce The production output of the cell factory reduces the profit of the enterprise

[0003] Diffusion process is an important method to make the PN junction of solar cells. However, the temperature required by the conventional diffusion process is too high, resulting in lattice defects in crystalline silicon. At the same time, a large amount of nitrogen and oxygen gas needs to be introduced during the diffusion process. Thick dead layer (oxide layer), which will reduce the conversion efficiency of solar energy