LEED/AES Studies of the Ge on Si(111)7×7 Surface

Abstract

Germanium was evaporated on the clean Si(111)7×7 surface at room temperature. With increase in Ge coverage θ, the intensity of the Si(LVV) AES signal decreased in accordance with a 2-dimensional growth mode up to a few monolayers, and the LEED pattern gradually changed from the (7×7) structure to a diffused (1×1) one at θ<2 monolayers and to an nonstructural one at θ>2. The LEED pattern and the AES intensity drastically changed by annealing. The Si(111)7×7 surface covered by 2 monolayers of Ge shows a (5×5) structure by annealing at temperature between 380 and 720°C.