采用低温缓冲层技术在Si衬底上生长高质量Ge薄膜  

Growth of high quality Ge epitaxial films on Si substrate by low temperature buffer technique

作　　者：周志文[1] 贺敬凯[1] 李成[2] 余金中[3] 

机构地区：[1]深圳信息职业技术学院电子通信技术系,广东深圳518029 [2]厦门大学物理系,福建厦门361005 [3]中国科学院半导体研究所,集成光电子学国家重点实验室,北京100083

出　　处：《光电子．激光》2011年第7期1030-1033,共4页Journal of Optoelectronics·Laser

基　　金：国家重点基础发展研究计划资助项目(2007CB613404)

摘　　要：采用低温缓冲层技术,在Si衬底上生长了质量优良的Ge薄膜。利用原子力显微镜(AFM)、双晶X射线衍射(XRD)和拉曼散射等研究了薄膜的晶体质量。结果表明,由于无法抑制三维岛状生长,低温Ge缓冲层的表面是起伏的。然而,Ge与Si间的压应变几乎完全弛豫。当缓冲层足够厚时,后续高温Ge外延层的生长能够使粗糙的表面变得平整。在90 nm低温Ge缓冲层上生长的210 nm高温Ge外延层,表面粗糙度仅为1.2 nm,位错密度小于5×105cm-2,XRD的峰形对称,峰值半高宽为460 arc sec。High-quality and thick Ge epitaxial films are grown on Si substrates utilizing the low-temperature（LT） buffer technique by ultrahigh vacuum chemical vapor deposition（UHV-CVD） and are characterized by atomic force microscope,X-ray diffraction,and Raman spectroscopy.The results show that the LT Ge buffer is rough due to the three-dimensional islands formations,but the misfit stress is nearly fully relaxed.Fortunately,the rough LT Ge surface is effectively smoothed by subsequent growth at elevated temperature when the LT Ge buffer is thick enough and the compressive strain is largely relaxed.Finally,the 210 nm Ge epitaxial film with smooth surface（root-mean-square roughness of 1.2 nm）,low threading dislocation density（5×105 cm-2）,and sharp and symmetric X-ray diffraction peak（full width at half maximum of ～460 arc sec） is achieved on LT Ge buffer with thickness of 90 nm.

关 键 词：Ge薄膜 低温缓冲层技术 表面形貌 超高真空化学气相沉积(UHV-CVD) 

分 类 号：TN304[电子电信—物理电子学]