Abstract: A metal oxide semiconductor field effect transistor power device with a lightly doped silicon substrate includes a source region and a drain region. At least one field implanted island region is formed along the surface of the oppositely substrate between the source and drain regions with a field oxide region formed above the field implanted region, a dielectric layer and a gate electrode of matching configurations formed over the substrate, and self-aligned source drain regions implanted into the device with external electrodes connected thereto.

Abstract: A silicon semiconductor device has buried conductor lines formed therein. A layer of gate oxide, conductive structures, and spacer structures adjacent to the conductive structures on the gate oxide layer are formed. The substrate has implanted dopant ions of a relatively low level of surface concentration in the semiconductor material below the remainder of the conductive structures. The substrate has implanted dopant ions of a relatively medium level of surface concentration in the semiconductor material below the spacer structures. The substrate has implanted dopant ions of a relatively high level of surface concentration in the semiconductor material below the remainder of the substrate. Thus leakage is reduced by the profile of surface concentration of dopant in the semiconductor material of the substrate.