A Diffusion Process for Improving Square Resistance Uniformity

Abstract

The invention discloses a diffusion process for improving the uniformity of square resistance, which comprises the following steps: (1) heating up: inserting the textured silicon chip into a quartz boat, getting on the boat, and raising the temperature of the furnace tube to 750°C-795°C after entering the boat; ℃; (2) Dry oxygen oxidation: Oxidation with dry oxygen, dry oxygen flow rate 1800-2200ml / min, oxidation time 100-sec; (3) Wet oxygen oxidation: Oxidation with wet oxygen flow rate 1400- 1600ml / min, oxidation time 200sec; (4) Diffusion: Introduce dry oxygen, small nitrogen and large nitrogen for precipitation and diffusion, dry oxygen flow rate 600-900ml / min, small nitrogen flow rate 1200-1500ml / min, large nitrogen flow rate is 10000ml / min~15000ml / min, diffuse at a temperature of 750°C~795°C for 1200sec, the invention provides a method for improving the diffusion process quality, high uniformity and good uniformity of the square resistance of the edge and surrounding of the diffused silicon wafer Diffusion process that resists uniformity.

Description

technical field [0001] The invention relates to the technical field of crystalline silicon cell solar cell production, and in particular relates to a diffusion process for improving square resistance uniformity. Background technique [0002] In terms of the industrialization of crystalline silicon cells, high-temperature diffusion methods are usually used to prepare PN junctions, and the industrial preparation of high-resistance emitters with good inter-chip and intra-chip uniformity is an important way to improve battery conversion efficiency and electrical performance stability. It can improve the optimization space of the diffusion process as a whole, and can reduce the number of battery efficiency bins. According to the existing technology, in order to increase the production capacity, the spacing between silicon wafers is continuously reduced. The adjacent distance between silicon wafers is small, and the partial pressure ratio of doped atoms is small, resulting in a la...

AI Technical Summary

Problems solved by technology

The adjacent distance between silicon wafers is small, and the partial pressure ratio of doped atoms is small, resulting in a large gap between the doping concentration in the middle of the silicon wafer and the edge, poor diffusion process quality, low uniformity, and in production lines with high square resistance, Due to the higher square resistance, the non-uniform phenomenon increases, resulting in more uneven square resistance between the edge of the diffused silicon wafer and the surrounding area.

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