Patent ID: 8623732

Claim:
A method of making a laterally double diffused metal oxide semiconductor (LDMOS) transistor, the method comprising: forming a reduced surface field (RESURF) region of a first conductivity type in a second conductivity type semiconductor material, wherein the second conductivity type semiconductor material is located over an insulator layer, the insulator layer is located over a semiconductor substrate, a first portion of the second conductivity type semiconductor material remains below the RESURF region, a second portion of the second conductivity type semiconductor material remains above the RESURF region, and an opening in the RESURF region is present between the first and second portions of the second conductivity type semiconductor material, wherein the RESURF region is depleted by the first and second portions of the second conductivity type semiconductor material below and above the RESURF region; forming a first conductivity type well region, where the first conductivity type well region partially merges with the RESURF region such that the RESURF region remains on a portion of a bottom surface and a sidewall surface of the first conductivity type well region which is electrically coupled to the RESURF region; forming a gate over the second conductivity type semiconductor material, over the first conductivity type well region, and over the RESURF region; forming a second conductivity type source region in the first conductivity type well region; and forming a second conductivity type drain region over the opening in the RESURF region to allow a drain potential to spread through the opening to a full depth of the second conductivity type semiconductor material over the insulator layer to achieve a double RESURF action.