Solid-phase lateral epitaxy of chemical-vapor-deposited amorphous silicon by furnace annealing

Abstract

A single-crystalline silicon-on-insulator structure has been fabricated with solid-phase lateral epitaxy. Chemical-vapor-deposited amorphous silicon (CVD a-Si) deposited on a SiO2 stripe is crystallized by furnace annealing. A new CVD technique (clean CVD) has met the conditions required for solid-phase epitaxy; clean interface and reduction of impurities and microcrystallites in the a-Si film. In the case of a 4-μm-wide SiO2 stripe parallel to the 〈100〉 direction, the entire deposited layer grows epitaxially by low-temperature furnace annealing (550∼650 °C). In the case of a 10-μm-wide SiO2 stripe, the whole surface region also grows epitaxially, although the deep region partially becomes polycrystalline in areas distant from the open substrate surface. The grown-layer crystallinity is improved by subsequent high-temperature annealing.