Low-voltage diffusion furnace-based ultra-low concentration POCl3 high-temperature diffusion method

Abstract

The invention discloses a low-voltage diffusion furnace-based ultra-low concentration POCl3 high-temperature diffusion method, which comprises the following steps of (1) entering of a boat; (2) phosphorus deposition; (3) heating knotting; (4) cooling oxidation; and (5) discharging out of the boat. Aiming at the technical defects in an existing diffusion technology, comprehensive consideration is carried out from the aspects of carrier gas consumption, sheet resistance uniformity and stability and the like; the overall diffusion technology is optimized; phosphorus diffusion of ultra-low concentration POCl3 is achieved by low-temperature deposition and high-temperature sub-step anaerobic propulsion modes in a low-pressure environment of 50-100mBar; and the concentration of the POCl3 is only 10% of that of a conventional process. The low-voltage diffusion furnace-based ultra-low concentration POCl3 high-temperature diffusion method has the characteristics of low carrier gas consumption, good sheet resistance and junction depth uniformity, few in surface dead layers and the like; the open-circuit voltage Uoc of a battery sheet can be obviously improved; the carrier gas consumption is reduced; the process running time is shortened; and the sheet resistance uniformity and stability are ensured.

Description

technical field

[0001] The invention relates to the field of solar cell preparation, in particular to an ultra-low concentration POCl based on a low-pressure diffusion furnace 3 high temperature diffusion method. Background technique

[0002] As the core technology in the production process of crystalline silicon solar cells, the diffusion process is an important link in the production of PN junctions. In order to make an ideal and uniform PN junction, we must conduct in-depth research and improvement on the diffusion process, because the quality of the PN junction has the most important impact on the conversion efficiency of the battery. The development of diffusion furnace technology also affects the progress of crystalline silicon solar cell technology to a large extent. Therefore, the current research on diffusion uniformity at home and abroad is mainly reflected in the improvement of diffusion furnace technology.

[0003] The improvement of the diffusion process can i...

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