Temperature control method of Czochralski monocrystalline silicon

Abstract

The invention discloses a temperature control method of Czochralski monocrystalline silicon and aims to automatically adjust temperatures in a silicon single crystal isometric growth process. The temperature control method comprises the following steps: confirming an average crystal growth speed V, and outputting the average crystal growth speed V; setting a target crystal growth speed VS, and calculating the deviation delta V of the average crystal growth speed V and the target crystal growth speed VS; and according to delta V, confirming a power set value Pr, outputting the power set value Pr, and furthermore performing temperature adjustment. Compared with a conventional SP closed-loop control mode, the temperature control method of the Czochralski monocrystalline silicon, which is disclosed by the invention, has the advantages that 1, SP control is canceled, unstable factors are eliminated, the stability of a temperature control system can be improved, furthermore, the diameter ofa crystal can be well controlled, the pass percentage can be increased, and the production cost can be lowered; 2, a thermocouple is eliminated, and the equipment cost can be lowered; and 3, the automation degree of a Czochralski monocrystalline silicon furnace can be increased.

Description

technical field [0001] The invention belongs to the technical field of single crystal growth technology, and in particular relates to a temperature control method for Czochralski silicon single crystal. Background technique [0002] With the rapid development of the global economy, human demand for energy continues to grow, but fossil fuels such as coal, oil, and natural gas are gradually being exhausted. As a green energy, solar energy is being more and more accepted and applied by human beings, and has been paid more and more attention by countries all over the world and has been vigorously developed. Silicon single crystal is the initial raw material for manufacturing photovoltaic modules. [0003] Czochralski silicon single crystal is a silicon single crystal manufacturing process. The manufacturing process is to put polysilicon material into a quartz crucible, heat and melt to form liquid silicon material, and then undergo temperature adjustment, seeding, shouldering, ...

AI Technical Summary

Problems solved by technology

In the actual temperature control process, it is necessary to manually calculate the SP value through thermocouple measurement. Due to the measurement accuracy of the device and the influence of the thermal field environment, the actual measured SP value is inaccurate, and the temperature in the furnace cannot be accurately reflected to accurately control the power.

In addition, due to the serious hysteresis of the temperature and the hysteresis of the current control method, the entire temperature control system is severely hysteresis, and the temperature fluctuates, which in turn leads to unstable diameter control and affects product yield.

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