Patent ID: 7659596

Claim:
A semiconductor lateral device formed on a surface of a lightly-doped semiconductor substrate of a first conductivity type comprising: a device edge region of a semiconductor of the first conductivity type connected to a first electrode, wherein said device edge region and said electrode both encircle the semiconductor lateral device along a portion of the outer-edge of the semiconductor lateral device; a device central region of a semiconductor of a second conductivity type connected to a second electrode and located in the center of the semiconductor lateral device and enclosed by said device edge region; a surface voltage-sustaining region located on said substrate comprising: at least a semiconductor region of the second conductivity type located between said device central region and said device edge region, at least an insulator region covering at least a portion of the surface of the semiconductor region of the second conductivity type and varying in thickness and/or electric permittivity in the direction from said device central region to said device edge region, at least one conductive layer(s) partly covering the insulator and forming at least one terrace field plate, and at least one semiconductor region of the first conductivity type surrounded by the semiconductor region of the second conductivity type except where it is connected to at least one terrace field plate, where the part of the terrace field plate covering the insulator is vertically positioned above a portion being immersed in said insulator of a neighboring terrace field plate; wherein said semiconductor region(s) of the first conductivity type inside the surface voltage-sustaining region is(are) not fully depleted under a reverse voltage applied across said second electrode and said first electrode, and the electric potential of the non-depleted region of it(them) is(are) floating.