应变Si/(001)Si1-xGex价带结构

应变SiCMOS技术是当前国内外研究发展的重点,在高速/高性能器件和电路中有极大的应用前景。基于(001)面弛豫Si1-xGex衬底上生长的张应变Si的价带E(k)-k关系模型,研究获得了[100]和[001]晶向的价带结构及相应的空穴有效质量。结果表明,与弛豫材料相比,应变引起了应变Si/(001)Si1-xGex价带顶的劈裂,且同一晶向族内沿[001]和[100]两个晶向的价带结构在应力的作用下不再对称,相应的空穴有效质量随Ge组份有规律地变化。价带空穴有效质量与迁移率密切相关,该结论为Si基应变PMOS器件性能增强的研究及导电沟道的应力与晶向设计提供了重要理论依据。

Valence Band of Strained Si/(001) Si1-xGex

There has been a lot of interest in the strained Si CMOS technology lately,which has been widely adopted in the high-speed and high-performance devices and circuits.Based on the valence band E(k)-k relation of strained Si/(001)Si1-xGex,the valence band and hole effective mass along and directions were obtained.It was found that in comparison with relaxed Si,the valence band edge degeneracy was partially lifted,the asymmetry valence band structures along and directions occured and the corresponding hole effective masses changed with increasing Ge fraction due to strain.The results can supply valuable references to the investigation in the Si-based strained PMOS devices and the conduction channel design related to stress and orientation.