Patent attributes
A multi-layer semiconductor structure is disclosed for use in III-Nitride semiconductor devices, including a channel layer, a band-offset layer having a wider bandgap than the channel layer, a spacer layer having a narrower bandgap than the band-offset layer, and a cap layer comprising at least two sublayers. Each sublayer is selectively etchable with respect to sublayers immediately below and above, each sublayer comprises a III-N material AlxInyGazN in which 0≦x≦1, 0≦y≦1, and 0≦z≦1, at least one sublayer has a non-zero Ga content, and a sublayer immediately above the spacer layer has a wider bandgap than the spacer layer. Also described are methods for fabricating such semiconductor structures, with gate and/or ohmic recesses formed by selectively removing adjacent layers or sublayers. The performance of resulting devices is improved, while providing design flexibility to reduce production cost and circuit footprint.
