Formation of Ge-Sn alloy with high Sn content for obtaining direct bandgap

Ge_1-xSn_x films are very promising way of achieving IR detectors and emitters compatible with Si and CMOS technology. The major obstacle is low solubility of Sn in Ge. In this work we used laser engraver to obtain crystalline Ge_1-xSn_x films by local annealing the amorphous Ge/Sn multilayer. Optionally, carbon implantation into the film before annealing was used, with the aim to reduce local strain in the alloy and preclude Sn (and Ge) segregation.

Si-based structures

This research aims to develop devices based on silicon-on-insulator (SOI) technology, which requires, in particular, the formation of a (poly)crystalline silicon layer and a SiO₂ layer on a monocrystalline silicon wafer.

Raman spectrum from the (light) region of the original amorphous silicon (green curve) and the spectrum of the (dark) region crystallized by a scanning laser engraver (red curve).