Method of making silicon on sapphire field effect transistors with specifically aligned gates

摘要

The method comprises forming a blind hole in a sapphire substrate using a sulfur hexafluoride gas etchant and an etch mask comprising a single layer of silicon nitride. The blind holes are filled with epitaxially grown silicon and field effect transistors are laid out with their gates orthogonal to a line which is at a 45 DEG angle to a standard wafer flat, i.e. orthogonal to the projection of the "c" axis onto the "r" plane of the sapphire wafer.