Abstract: A III-nitride device is provided comprising a semiconductor substrate; a stack of active layers on the substrate, each layer comprising a III-nitride material; a gate, a source and a drain contact on the stack, wherein a gate, a source and a drain region of the substrate are projections of respectively the gate, the source and the drain contact in the substrate; and a trench in the substrate extending from a backside of the substrate (side opposite to the one in contact with the stack of active layers) to an underlayer of the stack of active layers in contact with the substrate, the trench completely surrounding the drain region, being positioned in between an edge of the gate region towards the drain and an edge of the drain region towards the gate and having a width such that the drain region of the substrate is substantially made of the semiconductor material.

Abstract: A III-nitride device is provided comprising a semiconductor substrate; a stack of active layers on the substrate, each layer comprising a III-nitride material; a gate, a source and a drain contact on the stack, wherein a gate, a source and a drain region of the substrate are projections of respectively the gate, the source and the drain contact in the substrate; and a trench in the substrate extending from a backside of the substrate (side opposite to the one in contact with the stack of active layers) to an underlayer of the stack of active layers in contact with the substrate, the trench completely surrounding the drain region, being positioned in between an edge of the gate region towards the drain and an edge of the drain region towards the gate and having a width such that the drain region of the substrate is substantially made of the semiconductor material.