Development of Crystal Growth Technique of Silicon by the Czochralski Method

摘要

We report on the Czochralski method for single silicon crystal growth and discuss heat and mass transfer and defect formation in the crystal. A reflector was used for separation of the heating and cooling areas in the furnace enabling us to speed up crystal growth. The melt flow to stabilize the temperature distribution in a crucible was controlled using transverse magnetic fields in a large-scale silicon Czochralski furnace. The setup allows for changes in important parameters of point defect formation to be made, such as vacancies and interstitials, by changing temperature and flow fields in the furnace. A numerical calculation was developed to predict the tendency for growth of a vacancy rich or interstitial rich crystal by estimating the value of the ratio between the growth rate and temperature gradient in the crystals.