Lateral overgrowth of germanium for monolithic integration of germanium-on-insulator on silicon

Abstract A technique to locally grow germanium-on-insulator (GOI) structure on silicon (Si) platform is studied. On (001) Si wafer, silicon dioxide (SiO 2 ) is thermally grown and patterned to define growth window for germanium (Ge). Crystalline Ge is grown via selective hetero-epitaxy, using SiO 2 as growth mask. Lateral overgrowth of Ge crystal covers SiO 2 surface and neighboring Ge crystals coalesce with each other. Therefore, single crystalline Ge sitting on insulator for GOI applications is achieved. Chemical mechanical polishing (CMP) is performed to planarize the GOI surface. Transmission electron microscopy (TEM) analysis, Raman spectroscopy, and time-resolved photoluminescence (TRPL) show high quality crystalline Ge sitting on SiO 2 . Optical response from metal–semiconductor–metal (MSM) photodetector shows good optical absorption at 850 nm and 1550 nm wavelength.