论文部分内容阅读
热场模拟在物理气相输运法(PVT法)制备SiC单晶工艺的改进中起着重要的作用。实验中发现,SiC晶体生长表面可能会起伏不平,导致生长的晶体质量下降。经分析可知,籽晶固定过程中籽晶背面形成的气孔是造成晶体生长表面起伏不平的主要因素。热场模拟发现,在籽晶背面有气孔处,籽晶生长面温度较高。气孔宽度、籽晶厚度及粘结剂厚度影响籽晶表面气孔中心与气孔边缘的温差。减小气孔、增厚籽晶可有效减小籽晶表面气孔中心与气孔边缘的温差,是改善晶体生长面质量的两个有效途径。
Thermal field simulation plays an important role in the improvement of SiC single crystal preparation by physical vapor transport (PVT). The experiment found that SiC crystal growth surface may fluctuate, leading to the growth of the crystal quality decline. After analysis, we can see that the stoma formed on the back of the seed during the process of seed crystal fixation is the main factor causing the undulating surface of crystal growth. Thermal field simulation found that there are pores in the back of the seed, seed growing surface temperature is higher. Stomatal width, seed thickness and binder thickness affect the temperature difference between the stomata center and the stomata edge on the seed surface. Reducing the stomata and thickening the seed crystals can effectively reduce the temperature difference between the stomata center and the stomata edge, and are two effective ways to improve the quality of the crystal growing surface.