Giant growth of single crystalline Ge on insulator by seeding lateral liquid-phase epitaxy

Giant growth (∼ 400 μm length) of single crystalline Ge on insulator (GOI) with (100), (110), and (111) orientations is demonstrated by lateral liquid-phase epitaxy (L-LPE) using Si(100), (110), and (111) substrates, respectively, as the seeds. The micro-probe Raman measurements and transmission electron microscopy observations showed that the growth regions were of very high crystal quality and were defect free. In addition, lateral diffusion of Si atoms was observed only in the regions near the seeding edges (∼ 100 μm). Based on these findings, the trigger for the giant growth of the high-quality GOI was discussed considering the solidification temperature gradient due to Si-Ge mixing and the thermal gradient due to the latent heat at the growth front.