热交换法生长c面取向大尺寸蓝宝石晶体的研究

本文使用热交换法直接生长c面取向,尺寸为φ170 mm× 160 mm,重12 kg的蓝宝石晶体.晶体无色透明,内部无散射颗粒.沿c面(0001)方向的晶棒锥光图可观察到同心圆簇的干涉条纹,仅中心较小区域因内应力存在,干涉条纹发生扭曲.将抛光的晶片进行化学腐蚀后,通过金相显微镜检测位错腐蚀坑形貌图,结果显示,腐蚀坑呈三角形,平均位错密度较低,为1.98 × 103 Pits/cm2,X射线衍射半峰宽较小,晶体结构完整.

Study on c-plane Large Size Sapphire Growth by Heat-exchange Method

The c plane sapphire with size of 170 mm×160 mm,weight of 12 kg was grown by heat-exchange method.The crystal is transparent,and no particle/bubble in the crystal.According to the interference figure,the fringes are distorted in the center of the crystal because of the stress.After the chemical etching,the triangular etch pits appears through the microscope,and the etch pits density is low,just 1.98×103 Pits/cm2.The FWHM is so narrow,the crystal quality is good.