紊流模型模拟分析旋转对提拉大直径单晶硅的影响

本文采用紊流模型对提拉大直径单晶硅时,对晶体旋转、坩埚旋转及二者共同作用三种情况下,熔体内的流线、等温线、氧的浓度分布、紊流粘性系数、紊动能等作了数值模拟,发现晶体的旋转能提高氧的径向均匀性,紊流粘性系数和紊动能随着坩埚转速的提高先增加后下降.晶体坩埚同时旋转时并不能有效降低紊流粘性系数,但能使子午面上的流动受到抑制,等温线更为平坦,有利于晶体生长.

Numerical Simulation on the Effect of Rotation in a Czochralski Silicon Crystal Growth with a Turbulence Model

A turbulence model was used to simulate the Czochralski silicon crystal growth. The effects of crystal rotation, crucible rotation and the combination of crystal rotation and crucible rotation on the melt convection, oxygen transportation, turbulent kinetic energy and turbulent viscosity were studied. It is found that a crystal rotation can make the oxygen concentration more uniformly distributed at the crystal growth interface. A crucible rotation first increases turbulence viscosity and turbulence kinetic energy but decreases them after the further increase of the crucible rotation rate. The combined rotations of crystal and crucible do not decrease turbulence viscosity and turbulence kinetic energy, but they slow down the convection in the meridian plane and decrease the temperature gradient at the growth interface which are favorable to the crystal growth.