InAs薄膜的分子束外延生长与表面形貌及表面重构分析

MBE Growth and STM Analysis of Surface Morphology and Reconstructions of InAs Films

利用带有反射高能电子衍射(RHEED)仪的分子束外延(MBE)方法,通过RHEED图像演变实时监控薄膜生长状况,采用RHEED强度振荡测量薄膜生长速率,在InAs(001)基片上同质外延InAs薄膜。利用扫描隧道显微镜(STM)对MBE生长的InAs薄膜表面形貌以及表面重构进行扫描分析,证实样品表面为原子级平整,并指出样品表面处于β2(2×4)与α2(2×4)两种重构混合的重构相。

InAs films were prepared on InAs （001） substrate by utilizing the molecular beam epitaxy（MBg） technology. During the growth process of InAs films, reflection high energy electron diffraction （RHEED） intensity oscillations and patterns were used to measure and monitor the real-time growth rate and status. After growth and subsequent annealing, the sample was quenched down to room temperature then transferred into scanning tunneling microscope（STM） for observation. STM images confirmed that the surface morphology of this sample was atomically flat. Combined the RHEED patterns with STM images, it is speculated that the surface reconstruction of InAs films was mixture ofβ2 （2）〈 4） and a2 （2 X 4）.