掺锗CZSi原生晶体中氧的微沉淀  

Micro-Precipitation of Oxygen in As-Grown CZSi of Doping Ge

作　　者：张维连[1] 李嘉席[1] 陈洪建[1] 孙军生[1] 张建新[1] 张恩怀[1] 赵红生[1] 

机构地区：[1]河北工业大学材料学院半导体材料研究所,天津300130

出　　处：《Journal of Semiconductors》2002年第10期1073-1077,共5页半导体学报（英文版）

基　　金：河北省自然科学基金 (批准号 :5 0 0 0 16 );国家自然科学基金 (批准号 :5 9772 0 37)资助项目~~

摘　　要：利用锗硅单晶 (锗浓度约为 10 19cm-3 )切制成的籽晶和一般无位错硅单晶生长的缩细颈工艺以及从晶体头部至尾部平稳降低拉速的工艺 ,生长了直径为 6 0、5 0和 40mm ,掺锗量为 0 1%和 0 5 % (锗硅重量比 )的锗硅单晶 .利用化学腐蚀 金相显微镜法、扫描电子显微镜 (SEM)能谱分析和X射线双晶衍射等方法观测了掺锗硅的原生晶体中缺陷及氧的沉淀的状况 .发现用CZ法生长的锗硅原生晶体与常规工艺生长的CZSi晶体不同 ,体内存在着较高密度的氧微沉淀 .在晶体尾部 ,由于锗的分凝使熔体中锗高度富集 ,出现了“组分过冷”现象 ,在晶粒间界应力较大处有锗的析出并出现了枝状结晶生长 .晶体中高密度氧的微沉淀经过 12 5 0℃热处理 1h后会溶解消失 .A discussion is presented of the experiment results which CZSi single crystal of doping Ge up to 0.1～0.5% is grown using Czochralski technology.In order to control homogeneity of Ge distribution in Si,and ensure successfully growing of GeSi crystal,the crystal growth rate is lowed to less than 0.8mm/min.Crystal defects are observed by SEM and X-ray double-crystal diffraction,and oxygen content the crystals are measured by FTIR.The results indicate that the density of oxygen micro-precipitation in the SiGe crystal bulk is very large,which is different from that of CZSi grown by conventional technique.The reason is that growth rate of SiGe crystal was lower than that of conventional CZSi(～2mm/min).Because of a high degree of concentration of Ge in Si melt (segregation coefficient of Ge in Si, K _ Ge <1),dendritic growth and constitutional super-cooling are observed in the tail of crystal.

关 键 词：掺锗直拉硅 氧沉淀 分凝 晶体缺陷 CZ法 

分 类 号：TN305.2[电子电信—物理电子学]