Fabrication of reverse shallow trench isolation structures with super-steep retrograde wells

Abstract

Generally, the present disclosure is directed to methods for forming reverse shallow trench isolation structures with super-steep retrograde wells for use with field effect transistor elements. One illustrative method disclosed herein includes performing a thermal oxidation process to form a layer of thermal oxide material on a semiconductor layer of a semiconductor substrate, and forming a plurality of openings in the layer of thermal oxide material to form a plurality of isolation regions from the layer of thermal oxide material, wherein each of the plurality of openings exposes a respective surface region of the semiconductor layer.