Patent ID: 8835986
Filing Date: 2014-09-16
Classification: H01L

Abstract:
1. A III-nitride device comprising: a) a substrate comprising a semiconductor material; b) a stack of active layers on top of and in contact with the substrate, each of the active layers comprising a III-nitride material, wherein a transition between the stack of active layers and the substrate is an active-layer-stack/substrate interface; c) a gate contact, a source contact and a drain contact on the stack of active layers, wherein a gate region, a source region and a drain region of the substrate are projections of respectively the gate contact, the source contact and the drain contact in the substrate; and d) a trench in the substrate extending from a backside of the substrate, the backside being opposite to a side of the substrate that is in contact with the stack of active layers, up to an underlayer of the stack of active layers, the trench completely surrounding the drain region, such that the drain region is electrically isolated from the gate region and the source region across the active-layer-stack/substrate interface, and being positioned in between an edge of the gate region towards the drain region and an edge of the drain region towards the gate region, and having a width such that the drain region of the substrate substantially comprises the semiconductor material, wherein the trench has a width greater than or equal to a thickness of the stack of active layers and smaller than or equal to a distance between the edge of the gate region towards the drain and the edge of the drain region.