Spinel substrate and heteroepitaxial growth of iii-v materials thereon

Abstract

A spinel composition of the invention includes a monocrystalline lattice having a formula MgαAlβO, where w is greater than 0 and less than 1, x is greater than 2 and less than about 8, y is less than x, z is equal to or greater than about 4 and equal to or less than about 13, α is a divalent cationic element having an ionic radius greater than divalent magnesium, and β is a trivalent cationic element having an ionic radius greater than trivalent aluminum. The monocrystalline lattice has tetrahedral and octahedral positions, and most of the magnesium and α occupy tetrahedral positions. In one embodiment, the molar ratio of aluminum to the amount of magnesium, α and β can be controlled during growth of the monocrystalline lattice thereby forming a spinel substrate suitable for heteroepitaxial growth of III-V materials. A method of the invention, includes forming a monocrystalline lattice of a spinel composition. A composite includes the spinel composition layer and a III-V layer at the surface of the spinel layer. A method of forming a composite includes depositing the III-V layer onto the surface of the spinel composition using heteroepitaxial techniques.