Patent ID: 8580651

Claim:
A method of manufacturing a trench type semiconductor device, the method comprising: (i) providing a semiconductor substrate having first and second main surfaces opposite to each other, the semiconductor substrate having a heavily doped region of a first conductivity type at the second main surface and having a lightly doped region of the first conductivity type at the first main surface; (ii) forming a terminal structure over the first main surface side, formation of the terminal structure including formation of: (a) a gate electrode over the first main surface with a gate insulation layer interposed therebetween, (b) a body region of a second conductivity type at the first main surface adjacent to the gate electrode, (c) a source region of the first conductivity type in the body region, and (d) a body contact of the second conductivity type in the body region adjacent to the source region; (iii) after formation of the terminal structure, forming a mesa and a trench in the semiconductor substrate extending from the first main surface, with the terminal structure disposed generally over the mesa, the mesa being adjacent to the trench and having a first sidewall surface and a second sidewall surface; (iv) doping, with a dopant of the second conductivity type opposite to the first conductivity type, the first sidewall surface; (v) doping, with a dopant of the second conductivity type, the second sidewall surface; (vi) driving in the dopant at the first and second sidewall surfaces to respectively form a first doped region of the second conductivity type and a second doped region of the second conductivity; and (vii) following steps (i)-(vi), filling the trench with at least one of a semi-insulating material, an insulating material, and a combination thereof.