SiC单晶体放射状裂纹缺陷研究  

Study on the Radial Crack Defect in SiC Single Crystals

作　　者：张皓[1] 张政[1] 孙科伟 陈建丽[1] 孟大磊[1] 郭森 窦瑛[1] Zhang Hao;Zhang Zheng;Sun Kewei;Chen Jianli;Meng Dalei;Guo Sen;Dou Ying(The 46th Research Institute,CETC,Tianjin 300220,China)

机构地区：[1]中国电子科技集团公司第四十六研究所,天津300220

出　　处：《半导体技术》2020年第6期479-483,共5页Semiconductor Technology

摘　　要：在采用物理气相传输(PVT)法生长碳化硅(SiC)单晶的过程中,放射状裂纹是常见的缺陷。使用微分干涉显微镜对SiC单晶体和晶体抛光片表面形貌进行观测,结合晶体突变光滑面生长模型,对PVT法生长的SiC单晶放射状裂纹缺陷的形成机理进行了研究,并提出了消除或抑制放射状裂纹缺陷产生的方法。研究结果表明,放射状裂纹的出现与PVT生长过程中晶体微管密度紧密相关。在晶体生长初期,晶体生长平台平铺至尺寸较大的微管后形成微裂纹,这些微裂纹会随着晶体生长中的应力释放而沿晶体径向增殖、汇聚,最终与径向上的其他微裂纹连接成宏观放射状裂纹。通过提高SiC籽晶质量(低微管密度)、优化生长工艺参数可有效抑制放射状裂纹的产生。The radial crack is a common defect observed in SiC single crystals grown by the physical vapor transport(PVT)method.The surface morphologies of the SiC single crystal and polished wafers were observed by the differential interference contrast microscope.Combined with the step-flow and crystal plastic deformation model,a formation mechanism of radial crack defects in the SiC single crystal grown by the PVT method was studied,and a method for eliminating or suppressing the generation of radial cracks was proposed.The research results show that the generation of radial cracks is closely associated with the density of micropipes in the crystal during PVT growth.It was observed that in the initial growth stage,microcrack was generated after the crystal growth platform stepping to some large-size micropipes,which started to propagate and converge along the radial direction of the crystal as the stress released in the process of crystal growth until it connects with other microcracks in the radial direction to form the macroscopic radial cracks.The generation of the radial cracks can be effectively suppressed by using high quality(micropipe-free)SiC seeds and optimizing growth process parameters.

关 键 词：碳化硅(SiC) 物理气相传输(PVT) 放射状裂纹 晶体生长模型 微管 

分 类 号：TN304.24[电子电信—物理电子学]