Germanium on insulator (GOI) structure locally grown on silicon using hetero epitaxial lateral overgrowth

Abstract

A CMOS compatible technique for fabricating germanium (Ge) on insulator (GOI) structure that is locally implemented on silicon (Si) substrate is demonstrated. On a (100) crystalline Si substrate, silicon dioxide (SiO2) is thermally grown. Then growth window for Ge is defined by locally etching down the SiO2 to reveal the Si surface. Ge is grown epitaxially with multiple steps of high temperature hydrogen (H2) annealing. After growing Ge crystals fill the growth window, the growth proceeds laterally and, finally coalesces with the neighbouring Ge growth window. Thus crystalline Ge sitting on SiO2 is achieved. Chemical mechanical polishing (CMP) is used to planarize the surface, and wet etching is done to control the GOI film thickness.