Semiconductor device with field plate and multiple-part gate structure and method of fabrication therefor

Abstract

A semiconductor device includes a semiconductor substrate, source and drain electrodes, lower dielectric layer(s) disposed over an upper surface of the semiconductor substrate, and intermediate dielectric layer(s) disposed over the lower dielectric layer(s). The device also includes a multiple-part gate structure with lower and upper gate electrodes. The lower gate electrode is formed from a first portion of a first conductive layer. The upper gate electrode is formed from a second conductive layer. The device further includes a lower field plate disposed between the lower gate electrode and the drain electrode. The lower field plate is formed from a second portion of the first conductive layer. Methods of forming the semiconductor device enable the lower gate electrode and the lower field plate to be created in a self-aligned manner.