Abstract: A semiconductor structure a structure with an enhancement mode transistor device disposed in a first region and depletion mode transistor device disposed in a laterally displaced second region. The structure has a channel layer for the depletion mode and enhancement mode transistor devices. An enhancement mode transistor device InGaP etch stop/Schottky contact layer is disposed over the channel layer; a first layer different from InGaP disposed on the InGaP layer; a depletion mode transistor device etch stop layer is disposed on the first layer; and a second layer disposed on the depletion mode transistor device etch stop layer. The depletion mode transistor device has a gate recess passing through the second layer and the depletion mode transistor device etch stop layer and terminating in the first layer. The enhancement mode transistor device has a gate recess passing through the second layer, the depletion mode transistor device etch stop layer, the first layer, and terminating in the InGaP layer.

Abstract: A transistor structure comprising an active semiconductor layer with metal source and drain contacts formed in electrical contact with the active layer. A gate contact is formed between the source and drain contacts for modulating electric fields within the active layer. A spacer layer is formed above the active layer and a conductive field plate formed above the spacer layer, extending a distance Lf from the edge of the gate contact toward the drain contact. The field plate is electrically connected to the gate contact and provides a reduction in the peak operational electric field.

Abstract: A nitride-based semiconductor structure is provided. The structure includes an active layer that comprises an inverted quantum well structure that includes Indium and Nitrogen. The structure can be used to create a field effect transistor. In this case, the active layer forms an inverted active device channel. By including Indium and forming the inverted active device channel, a device having improved performance characteristics can be manufactured. Further, additional improvements, such as one or more additional layers, a second gate contact, and/or one or more field plates can be included in the device to obtain the desired performance characteristics.

Abstract: A semiconductor device includes an underlying layer made of a group-III nitride containing at least Al and formed on a substrate, and a group of stacked semiconductor layers including a first semiconductor layer made of a group-III nitride, preferably GaN, a second semiconductor layer made of AlN and a third semiconductor layer made of a group-III nitride containing at least Al, preferably AlxGa1-xN where x?0.2. The semiconductor device suppresses the reduction in electron mobility resulting from lattice defects and crystal lattice randomness. This achieves a HEMT device having a sheet carrier density of not less than 1×1013/cm2 and an electron mobility of not less than 20000 cm2/V·s at a temperature of 15 K.