Heat and Mass Transfer during Crystal Growth

摘要

Quality of semiconductor and oxide crystals which plays an important role for ectronic deveces are grown from the melts is significantly affected by the heat and mass transfer in the melts during growth by using Czochralski crystal growth systems, This paper reviews the present understanding of phenomena of the heat and mass transfer, especially melt convection from the results of flow visualization by using X-ray radiography to the details of numerical calculation needed for quantitative modeling of melt convection. Characteristics of flow instabilities of melt convection with a low Prandtl number are also reviewed by focusing on the instabilities of baroclinic, the Rayleigh-Benard and the Marangoni-Benard from points of view of temperature or rotating effects during crystal growth. The origin of the baroclinic instabily is reviewed based on geostrophic hydrodynamics, and it is discussed whether silicon flow is completely turbulent or has an ordered structure. Mass transfer in silicon melt is also discussed in the paper from microscopic point of view by molecular dynamics simulation using Stillinger-Weber potential.