Patent ID: 7439563
Filing Date: 2008-10-21
Classification: H01L

Abstract:
1. A high-breakdown-voltage semiconductor device comprising: a high-resistance semiconductor layer of a first conductivity type having a first main surface and a second main surface, a plurality of first trenches being formed on the first main surface of the high-resistance semiconductor layer in a longitudinal plane shape and in parallel with each other; a plurality of first semiconductor regions of the second conductivity type formed on the first main surface of the high-resistance semiconductor layer, each of the plurality of first semiconductor regions being sandwiched between adjacent trenches of the plurality of first trenches, and having an impurity concentration higher than that of the high-resistance semiconductor layer; a second semiconductor region of the first conductivity type disposed under at least a bottom portion of each of the plurality of first trenches and having an impurity concentration higher than that of the high-resistance semiconductor layer; a sidewall insulating film disposed on the sidewall of each of the plurality of first trenches; a third semiconductor region of the second conductivity type buried in the high-resistance semiconductor layer, a part of an upper surface of the third semiconductor region contacting a lower surface of the second semiconductor region and horizontally extending under the second semiconductor region to terminate below the first semiconductor region; a fourth semiconductor region disposed on the second main surface of the high-resistance semiconductor layer, and having an impurity concentration higher than that of the high-resistance semiconductor layer; a first electrode formed on each of the plurality of first semiconductor regions; a second electrode formed on and in direct contact with the second semiconductor region; a third electrode formed on the third semiconductor region and in contact with a surface thereof and a fourth electrode formed on the fourth semiconductor region.