Selective epitaxial growth of Si on sapphire using electron beam irradiation

Abstract

A new selective epitaxial growth method of silicon on sapphire by disilane gas-source molecular beam epitaxy (MBE) is proposed. Selective epitaxial growth of Si films on sapphire was achieved by irradiation of an electron beam on the sapphire surface before Si MBE. Si was not deposited on the sapphire surface irradiated by an electron beam, and was grown epitaxially only on the nonirradiated area. The selective epitaxial growth was confirmed by optical micrographs, in situ reflection high-energy electron diffraction, and Auger electron spectroscopy. It was recognized by x-ray photoelectron spectroscopy that the sapphire surface was changed before and after electron beam irradiation: oxygen atoms on the sapphire surface were decreased due to irradiation of the electron beam and aluminum atoms mainly existed on the surface. This phenomenon can be considered to be the main cause of the selective epitaxial growth.