Diffusion of Si into Ge studied by core level photoemission

Abstract

Ge(3d) and Si(2p) core level photoemission intensities were measured to monitor the coverage of Ge(001) and Ge(111) surfaces during the interrupted deposition of a thin Si film at room temperature and upon annealing. Annealing treatments were performed at temperatures up to a maximum of 880 K and interrupted a few times to allow for core level measurements. The Ge(3d) core level intensity was found to almost recover to its initial value upon annealing while the Si(2p) intensity decreased ∼60%. Intensity changes were observed at temperatures from 680 K upwards. It is concluded that above 680 K a significant diffusion of Si into Ge occurs, although at higher temperatures island formation or surface roughening also takes place.