Fabrication of crystalline Ge thin films by co-deposition of Au and Ge at low substrate temperatures (>200 °c) without post annealing

Crystalline Ge thin films with (111) orientation are obtained by co-depositing Au and Ge on a substrate heated to >170 °C, with Au segregating at the film surface, which is desirable for selective etching. Although in the conventional metal-induced crystallization method using Au as a catalyst, a bilayer of Au and amorphous Ge layers have to be annealed for Ge to crystallize, the film in this study is already crystalline in the as-deposited state. The effective crystallization process implies the existence of a supercooled liquid alloy layer at the growth front.