6H-SiC单晶生长温度场优化及多型控制

Temperature Field Optimization and Polytype Control in the Growth of 6H-SiC Single Crystal

本文模拟了升华法生长6H-S iC单晶的不同温度场,并进行了相应的生长实验。结果表明:改变石墨坩埚和感应线圈的相对位置,可以改变温度场形状;下移石墨坩埚;可以增大温度场径向温度梯度。在不同的径向温度梯度下,6H-S iC晶体分别以凹界面、平界面和凸界面生长。晶体生长界面的形状和速率影响晶体多型的产生,在平界面,生长速率小于300μm/h的晶体生长条件下,可获得无多型的高质量6H-S iC单晶。

Different temperature fields sublimation method in this paper. The are simulated for the growth of 6H-SiC single crystal via growth experiments were carried out in order to confirm the simulation results. It was shown that the morphology of the temperature field varied with the position of crucible in the reactor. For instance, the radial temperature gradient increased when the crucible was translated downwards. 6H-SiC crystals were grown with concave, fiat and convex interfaces corresponding to small, moderate and large radial temperature gradient respectively. The occurrence of parasite polytype in the single crystal is related to the shape of the solid-gas interface and the growth rate. High quality 6H- SiC single crystal without parasite polytype can be at the rate of less than 300μm/h. obtained when the crystal was grown with flat interface