Patent ID: 6710406
Filing Date: 2004-03-23
Classification: H01L

Abstract:
A trenched field effect transistor comprising:a semiconductor substrate having dopants of a first conductivity type; a trench extending to a first depth into said semiconductor substrate; a pair of doped source junctions having dopants of the first conductivity type, and positioned on opposite sides of the trench; a doped well having dopants of a second conductivity type opposite to said first conductivity type, and formed into the substrate to a second depth that is less than said first depth of the trench; and a heavy body formed in said doped well extending to a third depth that is less than said second depth of said doped well, the heavy body forming an abrupt junction with the well; wherein, a location of the abrupt junction relative to the depth of the well is adjusted so that a transistor breakdown initiation point is spaced away from the trench in the semiconductor, when voltage is applied to the transistor.