升华法生长大直径的SiC单晶  

Growth of large diameter SiC crystal by sublimation method

作　　者：李娟[1] 胡小波[1] 王丽[1] 李现祥[1] 韩荣江[1] 董捷[1] 姜守振[1] 徐现刚[1] 王继扬[1] 蒋民华[1] 

机构地区：[1]山东大学晶体材料国家重点实验室,济南250100

出　　处：《中国有色金属学报》2004年第F01期415-418,共4页The Chinese Journal of Nonferrous Metals

基　　金：国家"八六三"计划资助项目(2001AA311080);国家自然科学基金资助项目(60025409)

摘　　要：采用高纯Si粉和C粉在适宜的温度和压力下合成了多晶SiC粉末,在此基础上采用升华法在低压高温下条件下生长了大直径6H SiC单晶,并根据热力学理论分析了SiC的分解。结果表明,在2300℃附近的生长温度下,Si,Si2C,SiC2是Si C热力学平衡下的主要物种,其平衡分压比同组分的SiC物种高出3个量级,因而是升华过程中的主要物种,其质量传输过程直接决定SiC的生长。另外,采用光学显微镜观察SiC单晶中的生长缺陷,分析了缺陷成因,提出了碳的包裹体是微管缺陷的重要来源,而调制掺氮可以抑制部分微管在[0001]方向上的延伸,并在此分析基础上调整生长参数,生长出了高质量的6H SiC单晶。SiC powder was synthesized by using Si and C powder at favorable temperature and pressure. Then silicon carbide crystal was grown by the sublimation method under a low pressure and high temperature region. The decomposition reaction of SiC was simulated according to the thermodynamic theory. The result shows that the dominating species under thermodynamic equilibrium are Si ,SiC_2 and Si_2C at about 2 300 ℃. The equilibrium partial pressures of these three species are three magnitude degrees higher than those of the other species. Therefore, they are the main species during the sublimation process, and their mass flow determines the growth process. Furthermore, crystal defects were observed by optical microscopy. Carbon inclusions are the important origin of micropipes. It was found that the propagation of micropipes along the growth direction could be interrupted by modulation nitrogen doping. 6H-SiC of good quality is obtained after optimizing growth parameters.

关 键 词：升华法 SIC 微管 晶体生长 热力学 

分 类 号：TN304.2[电子电信—物理电子学]