Abstract: A semiconductor device comprises a heterostructure which includes first and second mutually separated conductive layers, e.g., active layers in which a respective two-dimensional electron gas can be induced. A source region and drain region each contact both conductive layers. A gate electrode is disposed between the source and drain regions. First and second output contact regions each contact both conductive layers. The first and second output contact regions are positioned between the source and drain and are overlapped by the gate electrode.