摘要
利用分子束外延技术,通过反射式高能电子衍射仪实时监控In0.86Ga0.14As/InAs薄膜生长状况,在InAs(001)基片上生长5、10、20原子单层(ML)厚度的InGaAs单晶薄膜。采用扫描隧道显微镜对原位退火后不同厚度的In0.86Ga0.14As样品进行扫描,证实了在同一组分下,薄膜生长厚度的改变并不剧烈影响薄膜的重构,然而,随着生长厚度的增加,外延层的表面拉伸应力进一步增大,平台平均尺寸逐渐减小,表面应力的累积使表面台阶数目逐渐增多,台面产生更多扭折,原子在具有各向异性的择优扩散机制与表面应力的共同作用下,In0.86Ga0.14As/InAs薄膜锯齿状的台阶边缘越明显,表面越粗糙化。
The growth of In0.86 Gao.14 As thin films by molecular beam epitaxiy（MBE）on InAs substrate was in-situ annealed and monitored with reflection high energy diffraction（RHEED）. The influence of the growth conditions, the film thickness in particular, on the atomic structures of the film surfaces was characterized with scanning tunneling microscopy （STM） .The results show that while slightly affecting the surface reconstruction,the thickness has a major impact on the microstructures and mechanical properties of the film surface. For example, as the thickness increased, the tensile inside the epitaxial layerincreased,but the average size of terrace decreased. Moreover, an increased number of steps with sharp irregular zigzag edgeswere observed, possibly because of accumulation of surface tensile and anisotropic preferred diffusion mechanisms.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2014年第4期363-366,共4页
Chinese Journal of Vacuum Science and Technology
基金
国家自然科学基金项目(6086601)
教育部博士点基金项目(20105201110003)
贵州省自然科学基金项目(No.20132092)
