Patent ID: 7728404
Filing Date: 2010-06-01
Classification: H01L

Abstract:
1. A semiconductor device comprising: a substrate of a first conductivity type; a first semiconductor region that includes a plurality of sub-regions of the first conductivity type that have a first doping concentration and a further semiconductor region of a second conductivity type opposite to the first conductivity type, the further semiconductor region separating the sub-regions from each other, the first semiconductor region located on the substrate; a second semiconductor region of the first conductivity type and having a second doping concentration which is lower than the first doping concentration, the second semiconductor region located on the first semiconductor region; a third semiconductor region of the second conductivity type and having a third doping concentration ranging between the first and the second doping concentration, the third semiconductor region located on the second semiconductor region; and a fourth semiconductor region of the first conductivity type and having a fourth doping concentration which is higher than the first doping concentration, the fourth semiconductor region located on the third semiconductor region, wherein the sub-regions extend from the second semiconductor region into the substrate, and wherein the thickness and the doping concentration of the second and the third semiconductor region are such that these regions are completely depleted during operation of the device.