Enhancement of Mg-induced lateral crystallization of amorphous germanium on an insulating substrate by two-step annealing

Abstract

Magnesium (Mg) induced lateral crystallization (Mg-ILC) of amorphous Ge on SiO2 stacked structure was investigated. From Raman mapping images, the critical annealing temperature necessary to induce Mg-ILC of amorphous Ge was estimated to be about 350 oC. Furthermore, the Mg-ILC length was truly narrow (~ 2 µm) compared with other metal catalyst after annealing at 350 oC for 1hour. To enhance the Mg-ILC, we have examined a two-step annealing method for Mg-ILC of amorphous Ge on SiO2. The Mg-ILC length is significantly enhanced (~ 4.5 times) by using a two-step annealing process, which is due to the enhancement of Mg diffusion into amorphous Ge during the first stage low temperature annealing.