Patent ID: 7199006
Filing Date: 2007-04-03
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device comprising: 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; forming in the semiconductor substrate a plurality of trenches and a plurality of mesas, each of the plurality of trenches having a first extending portion extending from the first main surface toward the heavily doped region to a first depth position, each of the plurality of trenches being disposed between adjacent mesas, each of the plurality of mesas having sidewall surfaces; implanting a dopant of the first conductivity type into a preselected mesa region of the semiconductor substrate at a sidewall surface of one mesa so as to form at the sidewall surface of the at least one mesa a first doped region of the first conductivity type having a doping concentration lower than that of the heavily doped region; implanting a dopant of the second conductivity type into the preselected mesa region at a sidewall surface opposite to the sidewall implanted with the dopant of the first conductivity type, to provide a second doped region of the second conductivity type at the sidewall surface opposite to the sidewall implanted with the dopant of the first conductivity type; oxidizing the sidewalls and bottoms of at least the trenches adjacent to the preselected mesa region and the top of the preselected mesa region to create a top oxide layer; etching back the top oxide layer to expose a preselected portion of the preselected mesa; depositing an oxide layer using a process selected from a group that includes tetraethylorthosilicate (TEOS) and spun-on-glass (SOG) oxide deposition to cover the etched back top layer and preselected mesa; and planarizing the top surface of the device.