A processing technology of silicon wafer with abnormal diffusion square resistance

Abstract

The invention relates to the manufacturing field of a silicon solar battery, and particularly relates to a treatment process for a silicon wafer with abnormal diffusion sheet resistance. The treatmentprocess comprises the following steps of 1, screening monocrystal silicon wafers with sheet resistance greater than or equal to 110-<omega> after diffusion; 2, preparing an HF solution with concentration of 5-20% to remove a phosphorosilicate glass layer from the surface, and performing acid washing on the monocrystal silicon wafers for 5-15min; and 3, after acid washing, leading the monocrystalsilicon wafers obtained in the step 2 into a quartz boat by an automatic rewinder, and performing melting down and diffusion by four steps of deposition, pushing in, re-deposition, and re-pushing-in in sequence. By virtue of the treatment process for the silicon wafer with abnormal diffusion sheet resistance, the diffusion supplementation successful rate is greatly improved.

Description

technical field [0001] The invention relates to the field of manufacturing silicon solar cells, in particular to a treatment process for a silicon wafer with abnormal diffusion square resistance. Background technique [0002] In the production of solar cells, due to factors such as equipment failure and unstable exhaust outside the power source, the diffusion resistance of the film is too large and exceeds the upper limit of the specification line. The current conventional technical solution is to directly perform supplementary expansion without any surface treatment; but When performing supplementary expansion directly, because there is already a layer of PSG (phosphosilicate glass layer) on the surface of the silicon wafer, P atoms cannot pass through the PSG (phosphosilicate glass layer) smoothly, resulting in little change in square resistance and a high failure rate of supplementary expansion; Some supplementary expansion schemes use the same temperature supplementary e...

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Problems solved by technology

[0003] The purpose of the present invention is to overcome the problem that P atoms cannot pass through the PSG (phosphosilicate glass layer) smoothly due to the existing layer of PSG (phosphosilicate glass layer) on the surface of the silicon wafer during the supplementary expansion of silicon wafers with abnormal diffusion square resistance. As a result, the square resistance changes little and the failure rate of supplementary expansion is high, and a treatment process for silicon wafers with abnormal diffusion square resistance is provided. This treatment process can remove the PSG (phosphosilicate glass layer) on the surface of the silicon wafer, making it easier for P atoms to Doping into the surface of the silicon wafer, reducing the diffusion resistance to the specified range by supplementing the concentration of P atoms, while ensuring the depth of the PN junction

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