Method of forming single crystalline magnesia spinel film

Abstract

The present invention relates to a method of forming a single crystalline magnesia spinel film on a single crystalline silicon substrate by the use of the vapor-phase epitaxial method. According to the method of the present invention, at first a first single crystalline magnesia spinel layer having a compositional ratio of magnesium maintained at a nearly stoichiometric compositional ratio is epitaxially grown in a vapor-phase on the single crystalline silicon substrate, and then a second single crystalline magnesia spinel layer having a compositional ratio of magnesium which decreases upward is epitaxially grown in a vapor-phase on the first single crystalline magnesia spinel layer. In the event that a Si film is grown on the single crystalline magnesia spinel film formed by the method of the present invention, out of atoms of Mg and Al taken in the Si film in the initial growth stage of the Si film, a concentration of Mg atoms which react more actively upon Si can be reduced. As a result, a reaction between Si and Mg can be suppressed to prevent the Si film from deteriorating its quality, whereby a SOI film having superior quality can be obtained.

Dependencies are inferred from the claim text.