Low temperature rapid formation of Au-induced crystalline Ge films using sputtering deposition

We report low temperature (100–170 °C) and rapid (10 min) formation of crystalline Ge films between Au catalyst film and quartz glass substrate using a radio frequency magnetron sputtering deposition. The formation rate of crystalline Ge films between Au catalyst film and quartz glass substrate is proportional to the deposition rate of Ge film, namely the flux of Ge atoms. To obtain insights on the formation mechanism of crystalline Ge films, we studied dependence of grain size of Au films on annealing temperature and Au film thickness. Crystalline Ge films formed below Au films have random crystalline orientation with in-plane grain size from below 1 μm. Small crystalline grain size of Au films is needed to form rapidly Au induced crystalline Ge films.