Method for monitoring concentration of hydrofluoric acid solution

Abstract

The invention discloses a method for monitoring concentration of a hydrofluoric acid solution. When the concentration of the hydrofluoric acid solution in a hydrofluoric acid solution tank confirms toa phosphorus silicon glass layer removal process, the hydrofluoric acid solution in the hydrofluoric acid solution tank is taken out by a drip tube and is drop onto a surface of a silicon wafer covered with a water film and provided with the phosphorus silicon glass layer, the time when the hydrofluoric acid solution and the phosphorus silicon glass layer on the surface of the silicon wafer reactto form a hydrophobic ring on the surface of the silicon wafer is timed, the timed time segment is defined as standard critical time t whether the hydrofluoric acid solution is normal, and it is shown that the concentration of the hydrofluoric acid solution in the hydrofluoric acid solution tank is normal if the time when reaction is performed to form the hydrophobic ring on the surface of the silicon wafer is smaller than the standard critical time t during the manufacturing process of a solar cell piece. According to the method for monitoring the concentration of the hydrofluoric acid solution, whether the concentration of the hydrofluoric acid solution can reach standard or not can be timely and accurately judged, so that the completion effect of the phosphorus silicon glass process isensured.

Description

Technical field: [0001] The invention relates to the field of solar cells, in particular to a method for monitoring the concentration of hydrofluoric acid solution in a solar cell pickling tank. Background technique: [0002] At present, in the manufacturing process of solar cells, a diffusion process is required, and the diffusion process involves the formation of a PN junction. At the same time, under this process condition, a phosphosilicate glass layer will be formed on the surface of the silicon wafer. The main component of the phosphosilicate glass layer is doped Phosphorous SiO 2 Glass. And the phosphosilicate glass layer (SiO 2 Glass layer) has hydrophilic properties, that is, water can evenly cover the phosphorosilicate glass layer (SiO 2 Glass layer) on the surface of the silicon wafer to form a water film covering layer. [0003] During the manufacturing process of solar cells, it is necessary to remove the phosphosilicate glass layer (SiO 2 Glass layer) tech...

AI Technical Summary

Problems solved by technology

The prior art is comparatively loaded down with trivial details when confirming whether the hydrofluoric acid solution concentration of the hydrofluoric acid solution tank meets the production process requirements, and deviations are prone to occur due to removal of the phosphosilicate glass layer (SiO2) on the surface of the silicon wafer. 2 Glass layer) quality problems of solar cells caused by unclean removal