Large grain growth of Ge-rich Ge_(1-x)Sn_x(x≈0.02) on insulating surfaces using pulsed laser annealing in flowing water

摘要

We investigate Sn incorporation effects on the growth characteristics of Ge-rich Ge_(1-x)Sn_x (x ＜ 0.02) on SiO_2 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 (～800nmφ) growth of Ge_(0.98)Sn_(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.