摘要
系统分析了Si1-xGex/Si外延生长中热应力对外延生长的影响.假设SiGe的线膨胀系数是随Ge的组分线性变化的,由此计算出热应变和应变能密度.根据能量平衡原理,当失配应变能密度加热应变能密度等于位错能密度时,外延层达到临界厚度,在People的基础上得出了改进的临界厚度计算公式.理论计算值与People的实验值更相近.
Effect of thermal strain on growth of SiGe strained layer on Si was analysed.Formulae for critical layer thickness were obtained by considering thermal strain in energy balance under the assumption of screw dislocation energy density equal to the sum of areal strain energy density and thermal strain energy density.The relationship between the thermal expansion coefficient associated with thermal strain and Ge content x was linear.The results are in good agreement with the experimental results reported.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第10期2010-2014,共5页
Acta Physica Sinica
基金
国家自然科学基金
国家教育委员会跨世纪优秀人才培养计划