Methods and apparatus for LDMOS devices with cascaded RESURF implants and double buffers

摘要

LDMOS devices are disclosed. An LDMOS device includes at least one drift region disposed in a portion of a semiconductor substrate; at least one isolation structure at a surface of the semiconductor substrate; a D-well region positioned adjacent a portion of the at least one drift region, and an intersection of the drift region and the D-well region forming a junction between first and second conductivity types; a gate structure disposed over the semiconductor substrate; a source contact region disposed on the surface of the D-well region; a drain contact region disposed adjacent the isolation structure; and a double buffer region comprising a first buried layer lying beneath the D-well region and the drift region and doped to the second conductivity type and a second high voltage deep diffusion layer lying beneath the first buried layer and doped to the first conductivity type. Methods are disclosed.