【作者】 王丽； 胡小波； 董捷； 李娟； 姜守振； 李现祥； 徐现刚； 王继扬； 蒋民华；

【Author】 WANG Li, HU Xiao-bo, DONG Jie, LI Juan, JIANG Shou-zhen, LI Xian-xiang,XU Xian-gang, WANG Ji-yang, JIANG Min-hua (State Key Laboratory of Crystal Materials, Shandong University, Ji’nan 250100, China)

【机构】 山东大学晶体材料国家重点实验室；

【摘要】 利用激光拉曼光谱仪测量了SiC单晶中不同多型的显微Raman光谱。在Raman光谱中,最大强度的FTA模和FTO模应出现在其简约波矢x等于该多型的六角度h处,据此时4H-SiC单晶中的多型进行了鉴定。同时采用高分辨X射线衍射测量了该晶片不同区域的摇摆曲线,将不同多型体的计算衍射角与实验值加以比较,对SiC晶片中的多型进行了标注,所得结论与激光Raman光谱测定结果相一致,说明Raman光谱是一种简单、快速地鉴定多型结构的强有力的工具。实验结果表明,在升华法生长4H-SiC单晶过程中,容易出现寄生6H、15R.多型同4H多型的竞争生长,简单分析了寄生多型产生的原因。更多还原

【Abstract】 Micro-Raman spectroscopy has been applied to identify polytypes in SiC single crystal grown by the seeded sublimation technique. The identification rule is that the value of the reduced wave vector for the FTA (folded transverse acoustic) mode and FTO (folded transverse optic) mode having the maximum intensity is equal to the hexagonality of the polytype. The rocking curves of different area have been measured by high resolution X-ray diffractometry. The reflections were indexed, furthermore the polytype structures were identified. The results are consistent with those of Raman spectroscopy analysis. It is demonstrated that Raman spectroscopy is a simple and powerful method for the determination of SiC polytypes. It is shown that 6H-SiC and 15R-SiC are the parasitic polytypes in 4H-SiC crystal. A simple explanation for the reason of parasitic polytypes formation has been given.更多还原