单晶硅衬底上Ge填埋层低温应力诱导重结晶制备多晶硅薄膜  

Low Temperature Stress-induced Re-crystallization of Poly-Si Thin Films on c-Si Wafer with a Buried Ge Layer

作　　者：孙启利[1] 邓书康[1] 申兰先[1] 胡志华[1] 李德聪[1] 晒旭霞[1] 孟代义[1] 

机构地区：[1]云南师范大学教育部可再生能源材料先进技术与制备重点实验室,昆明650092

出　　处：《人工晶体学报》2013年第6期1082-1086,共5页Journal of Synthetic Crystals

基　　金：the International Cooperation in Science and Technology Project(2011DFA62380)

摘　　要：本文采用电子束蒸发法,室温下在Si(400)的基片上生长含锗(Ge)填埋层的非晶硅薄膜,其结构为a-Si/Ge/Si substrate,并在真空中进行后续退火。采用Raman散射(Raman Scattering)、X射线衍射(X-ray Diffraction)、高分辨电子扫描显微镜(HRSEM)、光学显微镜和热重差热分析(DSC)等手段,研究退火后样品晶化特性和晶化机理。结果表明,室温下生长的含有250 nm Ge填埋层的生长态样品在400℃退火5 h,薄膜基本全部实现晶化,并表现出明显的Si(111)择优取向。样品分别在400℃、500℃、600℃和700℃退火后薄膜的横向光学波的波峰均在519cm-1附近,半高宽大约为6.1 cm-1,且均在Si(111)方向高度择优生长。退火温度为600℃的样品对应的晶粒尺寸约为20μm。然而,在相同的薄膜结构(a-Si/Ge/Si substrate)的前提下,当把生长温度提高到300℃时,温度高达到700℃退火时间5 h后,薄膜依然是非晶硅状态。差热分析表明,室温生长的样品,在后续退火过程中伴随界面应力的释放,从而诱导非晶硅薄膜重结晶成多晶硅薄膜。In this work,silicon thin films with a buried Germanium (Ge) layer were deposited on c-Si wafer (Si/Ge/c-Si) with an orientation of (400) by using electron beam evaporation (EBE) technique. The re-crystallization properties and mechanism upon annealing were investigated by Raman scattering, X-ray diffraction (XRD) ,high-resolution scanning electron microscopy (HRSEM) ,optical microscopy and differential scanning calorimetry (DSC) analysis. The results indicated that samples grown at lower substrate temperature (i. e. ambient temperature) contained a ～ 250 nm thick buried Ge layer are recrystallized with a preferential orientation of Si (111) at an annealing temperature of above 400 ℃ . Transverse optical (TO) peak of all Si thin films annealed at temperature of 400 ℃ ,500 ℃ ,600 ℃ and 700 ℃ are located around 520 cm - 1 ,and the full width half maximum (FWHM) are about 6. 1 cm - 1 , specifically,samples annealed at 600 ℃ possessed a higher preferential orientation of Si (111) ,and the corresponding grains size reaches 20 μm. However,as increasing the substrate temperature to 300 ℃ ,no re-crystallization was observed upon an annealing temperature of 700 ℃ even for 5 h. DSC analysis revealed that the re-crystallization upon annealing is induced by stress release.

关 键 词：多晶硅薄膜 应力诱导 非晶硅 电子束蒸发 

分 类 号：O484[理学—固体物理]