Patent ID: 7245243

Claim:
A lateral double-diffused MOS transistor comprising: a drift region of a first conductive type provided on a semiconductor substrate of a second conductive type; a body diffusion region of the second conductive type formed on a surface within the drift region; a gate electrode formed in such a position as it covers from part of the body diffusion region to part of the drift region located outside the diffusion region via an insulating film; and a source diffusion region of the first conductive type and a drain diffusion region of the first conductive type formed on top of the body diffusion region and top of the drift region, respectively, both of which correspond to both sides of the gate electrode, wherein the drain diffusion region includes a deep diffusion portion which has a 1/1000 or more concentration of a peak concentration of the source diffusion region and which is positioned deeper than the source diffusion region.