在Si(211)衬底上分子束外延CdTe的晶格应变  

Lattice Strain in MBE Grown CdTe Films on Si(211) Substrates

作　　者：王元樟[1] 陈路[1] 巫艳[1] 吴俊[1] 于梅芳[1] 方维政[1] 何力[1] 

机构地区：[1]中国科学院上海技术物理研究所功能材料与器件研究中心,上海200083

出　　处：《激光与红外》2005年第11期861-863,共3页Laser & Infrared

摘　　要：文章利用高分辨率X射线衍射技术对分子束外延CdTe(211)B/Si(211)材料的CdTe外延薄膜进行了倒易点二维扫描,并通过获得的对称衍射面和非对称衍射面的倒易空间图,对CdTe外延层的剪切应变和正应变状况进行了分析。研究发现,对于CdTe/Si结构,随着CdTe厚度的增加,[1-1-1]、[01-1]两个方向的剪切角γ[1-1-1]和[γ01-1]都有变小的趋势,且γ[1-1-1]的大小约为[γ01-1]的两倍;对于CdTe/ZnTe/Si,ZnTe缓冲层的引入可以有效地降低CdTe层的剪切应变。CdTe层的正应变表现为张应变,主要来源于CdTe和Si的热膨胀系数存在差异,而在从生长温度280℃降至室温20℃的过程产生的热应变。The shear strain and strain of MBE grown CdTe（211 ）B epilayers on 3inch Si（211 ） substrates are measured using reciprocal space maps in the symmetric and asymmetric reflection by high resolution X-ray diffraction. The results have showed that for C dTe/Si heterostructure, the shear angle γ[01-1] is about the half of γ[1-1-1] , and reduced with the increasing of CdTe film＇s thickness. For CdTe/ZnTe/Si heterostructure, the ZnTe buffer can reduce the shear strain in CdTe films effectively. The strain in CdTe is tensile strain when grown on Si substrates, due to the thermal strain which is originated from the difference in thermal expansion coefficients between epilayers and substrates during cooling from the growth temperature of 280℃ to room temperature 20℃.

关 键 词：CdTe/Si 倒易点二维扫描图 剪切应变 正应变 分子束外延 

分 类 号：O472.1[理学—半导体物理] TN304.054[理学—物理]