Patent ID: 6525397
Filing Date: 2003-02-25
Classification: H01L

Abstract:
A MOS transistor comprising:a bulk region having a first conductivity type and a first surface; a well region in the bulk region, the well forming a drain of the transistor, the well having a conductivity type opposite the bulk region; a recessed trench in the well region; an insulative material filling the trench, the insulative material including a top surface located coplanar with or below the first surface of the bulk region; a polysilicon layer extending over a portion of the bulk region and a portion of the trench; a first diffusion region in the well region, the first diffusion region being laterally spaced from the polysilicon layer by the trench, the first diffusion region having the same conductivity type as the well; and a second diffusion region in the bulk region, the second diffusion region forming a source of the transistor, the second diffusion region having a conductivity type opposite the bulk region.