摘要

Melt level plays an important role in the production of high-quality silicon crystals. In this paper, a systematic solution is proposed for silicon melt level measurement in Czochralski crystal pullers. First, a measuring principle based on laser triangulation using a line laser is analyzed, and the melt level is found to be in a linear relationship with a 'virtual distance' in captured images. Then, devices are chosen to form a system which overcomes the harsh measurement environment. In particular, the system adopts a Mo sheet to achieve wide measurement range. Subsequently, a unique signal detection approach is designed to calculate the melt level quickly from images. Melt surface fluctuation is taken into account and a Kalman filter is applied to provide an accurate measurement result. Application results have shown that the proposed system is not only simple in system calibration, but also accurate and robust in the measurement of silicon melt levels.

  • 出版日期2017-11
  • 单位流体动力与机电系统国家重点实验室; 浙江大学

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