Large grain growth of Ge-rich Ge_1-xSn_x (x 0.02) on insulating surfaces using pulsed laser annealing in flowing water

We investigate Sn incorporation effects on the growth characteristics of Ge-rich Ge_1-xSn_x (x<0.02) on SiO₂ crystallized by pulsed laser annealing (PLA) in air and water. Despite the very low Sn content of 2%, Sn atoms within the GeSn layers play a role in preventing ablation and aggregation of the layers during these PLA. Raman and electron backscatter diffraction measurements demonstrate achievement of large-grain (∼800nm) growth of Ge_0.98Sn_0.02 polycrystals by using PLA in water. These polycrystals also show a tensile-strain of ∼0.68%. This result opens up the possibility for developing GeSn-based devices fabricated on flexible substrates as well as Si platforms.