High speed mosfet power device with enhanced ruggedness fabricated by

Abstract

This invention discloses a MOSFET power device supported on a substrate. The MOSFET power device includes a plurality polysilicon-with-oxide-cap segments disposed over a gate oxide layer including two outermost segments and a plurality of inner segments include a plurality of gate oxide-plug openings. Each of the inner segments functions as agate and the two outer most segments function as a field plate and an equal potential ring separated by a termination oxide-plug gap and the gate oxide-plug openings and the termination oxide-plug gap having an aspect ratio greater or equal to 0.5. The MOSFET power device further includes a plurality of MOSFET transistor cells for each of the gates, wherein each transistor cells further includes a source region, a body region, the transistor cells further having a common drain disposed at a bottom surface of the substrate. Each of the inner segments functions as a gate having a side wall spacer surrounding edges of the inner segments, and the gate oxide-plug openings and the termination oxide-plug gap being filled with an oxide plug. The MOSFET transistor cells are covered by an overlying insulation layer having a plurality of contact openings defined therein. The MOSFET power device further includes a plurality of metal segments covering the overlying insulation layer and being in electric contact with the DMOS device through the contact opening. The MOSFET power device further includes a plurality of deep-and-narrow gaps between the metal segments wherein each gap having an aspect ratio equal to or greater than 0.5.