Control of lateral epitaxial chemical vapor deposition of silicon over insulators

Abstract

Single-crystal silicon films have been grown over SiO2-covered regions of a single-crystal silicon wafer by lateral epitaxial chemical vapor deposition (CVD). Nucleation of polycrystalline silicon on the SiO2 is suppressed by adding HCl to the SiH4 deposition gas. Sequential variation of the HCl partial pressure during different stages of the deposition process controls the relative deposition rates of the [100] and [110] planes and, consequently, the shape of the laterally advancing growth fronts, allowing the fronts from opposite sides of the SiO2 region to join uniformly. A plane surface is obtained by increasing the HCl partial pressure after coalescence. A standard silicon CVD epitaxial reactor is used for the deposition.