勾形磁场下提拉法生产单晶硅的数值模拟

本文给出了提拉单晶硅时,勾形磁场强度的计算公式,并对单晶硅在有无勾形磁场情况下熔体内流场和氧的浓度分布进行了数值模拟,计算出磁场作用下磁场强度和洛伦兹力及有无磁场时流函数、垂直截面处的速度场和氧的浓度分布.通过分析表明,勾形磁场能使流动更为平稳,能有效地降低熔体内及生长界面氧的浓度,并对产生这一现象的机理作了理论分析.

Numerical Simulation in Czochralski Si Melt under a Cusp Magnetic Field

The equations used to calculate the cusp magnetic field strength in the crystal silicon growth were given.Numerical calculation was carried out to investigate the melt convection and oxygen transportation in a Czochralski growth system with and without a cusp magnetic field. The cusp magnetic filed strength and Lorentz force at a vertical cross section were calculated and the stream function, velocity at a vertical cross section, oxygen concentration were also calculated. Numerical result shows that the melt flow is dramatically suppressed and the oxygen concentration at the growth interface decreases with the application of the cusp magnetic field. The mechanism of the reductions of the convection and the concentration of oxygen was analyzed.