| 摘要 |
PURPOSE:To provide a semiconductor device comprising high voltage MISFETs, having low ON resistance and occupation area, integrated on one chip. CONSTITUTION:A voltage lower than a breakdown voltage is applied between a drain electrode 25, a source electrode 24, a substrate 11 and a gate electrode 26 to extend a depletion layer from the junction between an extended drain region, i.e., an n<->-type diffusion region 13, and a p<->-type semiconductor substrate 11. When the depletion layers are extended from the junction between the extended drain region and a plurality of field rings 21, the depletion layers are interconnected thus depleting the extended drain region and the plurality of field rings across the their entire thickness at least locally. |
