Polycrystalline silicon ingoting process for shortening corner crystal growth time

Abstract

The invention belongs to the field of polycrystalline silicon ingoting, and particularly relates to a polycrystalline silicon ingoting process for shortening corner crystal growth time. The process comprises the following steps: loading, vacuum-pumping, preheating, melting and heat-insulating, crystal growth, annealing, temperature reduction and squaring, wherein the step of crystal growth comprises a central crystal growth stage and a corner crystal growth stage. The polycrystalline silicon ingoting process is characterized in that the next step of annealing stage can be performed after 1/4-1/6 of the corner crystal growth stage is completed. The ingoting process has the advantages as follows: 1, through shortening the time of the corner crystal growth stage, the annealing stage comes in advance, and the whole process time is effectively shortened by 2-3 h, and moreover, back diffusion of impurities at the ingoting top can be effectively prevented so as to improve the polycrystalline silicon ingoting quality; 2, as the process time is shortened, the expenditure on electric power and manual labour is reduced, and as a result, the cost of the whole ingoting process is reduced by 5 percent.

Description

technical field [0001] The invention belongs to the field of polysilicon ingot casting, and in particular relates to a polysilicon ingot casting process which shortens the crystal growth time at corners. Background technique [0002] At present, my country has become the world's largest energy production and consumption country, but the per capita energy consumption level is still very low. With the continuous development of the economy and society, my country's energy demand will continue to grow. In response to the current energy shortage, countries around the world are thinking deeply, and are working hard to improve energy efficiency, promote the development and application of renewable energy, and reduce the impact on energy consumption. Reliance on imported oil to enhance energy security. [0003] As one of the important development directions of renewable energy, solar photovoltaic power generation has developed rapidly in recent years, and its proportion is increasin...

AI Technical Summary

Problems solved by technology

Among them, it takes a long time in the crystal growth stage, generally more than 60 hours, which makes the cost of manpower and electricity in the ingot casting process remain high