Patent ID: 8530313

Claim:
A method of forming a semiconductor device comprising a plurality of first trenched gates surrounded by source regions of a first conductivity type near a top surface of a silicon layer of said first conductivity type encompassed in body regions of a second conductivity type in active area, said method comprising: applying a trench mask on said silicon layer and formation of a plurality of said first trenched gates in said active area, and at least a second trenched gate having wider gate trench than said first trenched gates in a gate runner metal area, and multiple third trenched gates in a termination area; after formation of said body regions, depositing a contact insulation layer on the top surface of said silicon layer; applying a contact mask and following with a dry oxide etching to remove said contact insulation layer from contact open areas; implanting said silicon layer with a source dopant of said first conductivity type through said contact open areas and diffusing said source dopant to form said source regions in said contact open areas in said active area, thereby a source mask is saved; and carrying out a dry silicon etch to form trenched source-body contacts in said contact open areas, penetrating through said source regions and extending into said body regions.