钨钼复合热屏对泡生法生长蓝宝石晶体质量的影响

Effect of Tungsten/Molybdenum Composite Heat Shield on Sapphire Crystal Quality Grown by Kyropoulos Method

热场结构决定了晶体生长的热量、质量传输条件和晶体生长环境。利用专业晶体生长模拟软件CGSim,用数值模拟技术分析了晶体的温度场和应力场,研究了全钼热屏和钨钼复合热屏热场结构对蓝宝石晶体生长的影响。结果表明:钨钼复合热屏能够提供均匀的温度场,降低了晶体内部轴向和径向温度梯度以及晶体表面温度梯度,减小晶体内的热应力,晶体质量明显提高。

The heat and mass transport in crystal growth and the environment of crystal growth are decided by thermal field structure in crystal growth furnace. The temperature and stress fields in sapphire crystal during crystal growth were analyzed via the numerical simulation by software named CGSim. The influence of thermal field structure of the tungsten heat shield and the tungsten/ molybdenum composite heat shield on the quality of the sapphire crystal was investigated. The results indicate that the tungsten/molybdenum composite heat shield can provide a uniform temperature filed, reduce the axial and radial temperature gradient of crystal and crystal surface temperature gradient, decrease the thermal stress in the crystal and improve the quality of sapphire crystal.