JPS6427256A - Semiconductor device - Google Patents

Abstract

PURPOSE:To increase the areas of electrodes, to elevate current density in a substrate and to augment output currents by disposing the electrodes for a high-voltage drive semiconductor element while being divided into both surfaces of the substrate. CONSTITUTION:A DMOS transistor 3 is formed by doubly diffusing P layers 21 as channel forming regions and N<+> layers 22 as source regions to an N<-> layer 20 as a drain region. The DMOS transistor 3 has vertical type structure, and source electrodes 23 and a drain electrode 24 are arranged divided onto both surfaces of a substrate. That is, the source regions 23 are shaped onto the surface of the substrate 4, and the drain electrode 24 is formed onto the rear of the substrate 4. Accordingly, the area of the drain electrode 24 can be increased while a margin can be formed on the surface of the substrate 4 by transfer onto the rear from the surface of the substrate 4 of the drain electrode 24, thus also augmenting the areas of the source electrodes 23 and the areas of electrodes 12-17 in a C-MOS transistor 2.