Fabrication of low-defect Ge-rich SiGe-on-insulator by continuous-wave diode laser-induced recrystallization

We develop a cost-effective, up-scalable and high-throughput method to fabricate low-defect Ge-rich SiGe-on-insulator (SGOI) through continuous-wave diode laser-induced recrystallization of sputtered Ge on Silicon-on-insulator (SOI). The successful formation of Ge-rich SGOI is revealed by Raman spectra and energy-dispersive X-ray spectroscopy mapping. Transmission electron microscopy measurements show that the fabricated SGOI has much lower dislocation density than the initial Ge film which may be attributed to two effects: i) laser-induced lateral recrystallization changing the mechanism from SiGe/Si hetero-epitaxy to SiGe/SiGe homo-epitaxy, ii) the fast regrowth rate and high thermal gradient producing vacancy supersaturation causing the movement of dislocations to lateral surfaces.