Patent ID: 9608102
Date: 2017-03-28
CPC Classifications: H01L

Claim:
1. A transistor, comprising: a substrate; a gallium nitride material region disposed over the substrate; a source electrode formed, at least in part, over the gallium nitride material region; a gate electrode formed, at least in part, over the gallium nitride material region; a drain electrode formed, at least in part, over the gallium nitride material region; a passivating layer formed over the gallium nitride material region between the source electrode and the gate electrode, and between the gate electrode and the drain electrode, the gate electrode extending over a portion of the passivating layer a distance directly on the passivating layer in a direction of the drain electrode greater than a distance in a direction of the source electrode; a source field plate situated, at least in part, over the source electrode and electrically connected to the source electrode by a conductive path formed through a dielectric layer formed over the source electrode, the dielectric layer adjoining the conductive path on all sides between the source field plate and the source electrode; a via extending through the gallium nitride material and the substrate to a backside of the substrate; conductive material disposed in the via and electrically connecting the source field plate to a conductive region at the backside of the substrate; and a barrier layer disposed on sidewalls of the via so as to separate the conductive material from the gallium nitride material region and the substrate, the barrier layer preventing chemical reactions between the conductive material and the substrate, the barrier layer comprising one or more of titanium, tungsten, nickel and platinum, wherein the source electrode is situated over the conductive material.