Patent ID: 7226816

Claim:
A method of producing an apparatus, comprising the steps of: forming a dielectric layer on a bulk semiconductor layer; forming a device layer on said dielectric layer; etching a trench through said device layer and said dielectric layer into said bulk layer, said trench having sidewall portions adjacent said dielectric layer and said device layer; forming an insulator layer having a first thickness on and covering an interior surface of said trench within at least said bulk layer; forming an insulator layer having a second thickness greater than said first thickness within said trench at least covering said sidewall portions adjacent said device layer above said bulk layer; filling said trench with conductive material to at least said insulator of said second thickness such that said conductive material is separated from said device layer at said sidewall portions by said insulator layer having said second thickness; and forming a first electrical contact to said conductive material and a second electrical contact to said bulk layer.