Semiconductor device with diffusion barrier layer and method of fabrication therefor

Abstract

A semiconductor device includes a semiconductor substrate with an upper surface and a channel, a dielectric layer disposed over the upper surface, and a diffusion barrier layer disposed over the dielectric layer. The diffusion barrier layer is patterned to include multiple segments. A gate electrode is formed over the semiconductor substrate and is electrically coupled to the channel. A drain opening is spatially separated from a first side of the gate electrode. A drain electrode, which also is electrically coupled to the channel, includes a first portion formed within the drain opening, and a second portion that overlies a segment of the diffusion barrier layer. A conductive field plate between the gate electrode and the drain electrode includes a field plate layer and another segment of the diffusion barrier layer. The drain electrode and the field plate layer may be formed from portions of a same conductive layer.