NITRIDE-BASED SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

A nitride-based semiconductor device includes a first and a second nitride-based semiconductor layers, a source electrode and a drain electrode, a gate structure, a passivation layer and a field plate. The passivation layer is disposed above the second nitride-based semiconductor layer and covers the gate structure and has an enclosed air gap between the gate structure and the drain electrode. The field plate is disposed above the passivation layer and has a first portion directly over the gate structure and a second portion directly over the air gap. The second portion is separated from the air gap by at least one dielectric of the passivation layer.