Thermal evolution of Fe on Ge(111)-c(2x8) surface and the effect of (√3×√3)Ag-Ge buffer layer
Hung-Chang, Hsu1*, Ming-­‐Kuan, Jhou1, Tsu-Yi, Fu1
1物理研究所, 國立台灣師範大學, 台北, Taiwan
* presenting author:許宏彰,
By using Scanning Tunneling Microscopy, we compare two systems that Fe deposits on a clean Ge(111)-c(2x8) surface and the surface with a (√3×√3)Ag buffer layer. It is easy to form complex surface alloy structure on Fe/Ge system during annealing from 300-650K. The similar surface morphology evolution for two different amount of Fe in the clean Ge(111) surfaces. In order to decrease the complex alloy phenomenon, we choose the (√3×√3)Ag-Ge interface as the buffer layer. With or without the buffer layer, very different growth morphology are found. After heat treatment between 300-650 K, the observable island volume per area on (√3×√3)Ag buffer layer is greater, but the increasing rate is much lower than the clean Ge(111)-c(2x8) surface. The results confirm that the (√3×√3)Ag buffer layer can avoid Fe adatom diffusing into the bulk and reducing Fe clusters catch Ge atoms out to surface forming alloy islands during annealing processes.

Keywords: STM, iron germanide, Ag