Patent ID: 8012848

Claim:
A method, comprising: (a) forming a trench in a silicon region of a substrate, said silicon region adjacent to a top surface of said substrate, said trench extending from said top surface of said substrate into said silicon region; (b) forming an insulating layer over said top surface of said substrate and on sidewalls and a bottom of said trench; (c) forming a stopping layer on said insulating layer; (d) removing said stopping layer from regions of said insulating layer over said top surface of said substrate and over said bottom of said trench, said stopping layer remaining on said insulating layer on said sidewalls of said trench, the remaining stopping layer recessed below said top surface of said substrate, said insulating layer exposed in said bottom of said trench; (e) filling remaining space in said trench with a dielectric fill material, said dielectric fill material not including any materials found in said stopping layer; (f) performing an N-type ion implantation on a first side of said trench into a first region of said silicon region abutting said first side of said trench and into a first region of said dielectric material abutting said insulating layer on said first side of said trench; (g) performing a P-type ion implantation on an second side of said trench into a second region of said silicon region abutting said second side of said trench and into a second region of said dielectric material abutting said stopping layer on said second side of said trench, said second side of said trench opposite said first side of said trench; and wherein said stopping layer comprises a material selected from the group consisting of nickel, cobalt, copper, chromium, molybdenum, palladium, silver, hafnium, tungsten carbide, tungsten nitride, gold, platinum, and combinations thereof.