Segregation control for ultrathin Ge layer in Al/Ge(111) system

Abstract

Abstract An impact of the vacuum anneal of Al/Ge(111) structure on the Ge segregation has been investigated to get an insight into the precise control of ultrathin Ge crystalline growth. The Al/Ge(111) structure was prepared by thermal evaporation of Al on wet-cleaned Ge(111) and then vacuum annealed without air exposure to promote Ge formation on the Al surface. The Ge formation and its chemical bonding features were evaluated by X-ray photoelectron spectroscopy analysis. In addition, changes in the average Ge thickness depending on annealing temperature and time were crudely estimated. We found that the annealing temperature had a greater effect than time on the control of sub-nanometer scale Ge growth.