Heterostructure and double-heterostructure trench-gate devices, in which the substrate and/or the body are constructed of a narrower-bandgap semiconductor material than the uppermost portion of the drift region. Fabrication most preferably uses a process where gate dielectric anneal is performed after all other high-temperature steps have already been done.

Techniques related to III-N transistors having enhanced breakdown voltage, systems incorporating such transistors, and methods for forming them are discussed. Such transistors include a hardmask having an opening over a substrate, a source, a drain, and a channel between the source and drain, and a portion of the source or the drain disposed over the opening of the hardmask.

A nitride-based semiconductor device includes a first nitride-based semiconductor layer, a single III-V group semiconductor layer, a third nitride-based semiconductor layer, a first source electrode and a second electrode, and a gate electrode. The second nitride-based semiconductor layer is disposed over the first nitride-based semiconductor layer. The single III-V group semiconductor layer is disposed between the first and second nitride-based semiconductor layers and doped to the first conductivity type. The single III-V group semiconductor layer has a high resistivity region and a current aperture enclosed by the high resistivity region, in which the high resistivity region comprises more metal oxides than the current aperture so as to achieve a resistivity higher than that of the current aperture. The third nitride-based semiconductor layer is disposed over the second nitride-based semiconductor layer. The first source electrode, the second electrode, and the gate electrode are disposed over the third nitride-based semiconductor layer.

A nitride-based semiconductor device includes a first nitride-based semiconductor layer, a second nitride-based semiconductor layer, a third nitride-based semiconductor layer, a passivation layer, a gate insulator layer, and a gate electrode. The first nitride-based semiconductor layer includes at least two doped barrier regions defining an aperture between the doped barrier regions. The second nitride-based semiconductor layer is disposed over first nitride-based semiconductor layer. The third nitride-based semiconductor layer is disposed on the second nitride-based semiconductor layer and has a bandgap higher than a bandgap of the second nitride-based semiconductor layer. The passivation layer is disposed over the third nitride-based semiconductor layer, in which a vertical projection of the passivation layer on the first nitride-based semiconductor layer is spaced apart from the aperture. The gate insulator layer is disposed over the third nitride-based semiconductor layer. The gate electrode is disposed over the gate insulator layer and aligns with the aperture.

A nitride-based semiconductor device includes a first nitride-based semiconductor layer, a lattice layer, a third nitride-based semiconductor layer, a first source electrode and a second electrode, and a gate electrode. The second nitride-based semiconductor layer is disposed over the first nitride-based semiconductor layer. The lattice layer is disposed between the first and second nitride-based semiconductor layers and doped to the first conductivity type. The lattice layer comprises a plurality of first III-V layers and second III-V layers alternatively stacked. Each of the first III-V layers has a high resistivity region and a current aperture enclosed by the high resistivity region. The high resistivity region comprises more metal oxides than the current aperture. At least two of the current apertures have different dimensions such that interfaces formed between the high resistivity regions and the current apertures misalign with each other. The gate electrode aligns with the current aperture.

A nitride-based semiconductor device includes a first nitride-based semiconductor layer, a lattice layer, a third nitride-based semiconductor layer, a first source electrode and a second electrode, and a gate electrode. The second nitride-based semiconductor layer is disposed over the first nitride-based semiconductor layer. The lattice layer is disposed between the first and second nitride-based semiconductor layers and doped to the first conductivity type. The lattice layer comprises a plurality of first III-V layers and a plurality of second III-V layers alternatively stacked. Each of the first III-V layers has a high resistivity region and a current aperture enclosed by the high resistivity region. The high resistivity region comprises more metal oxides than the current aperture. Interfaces formed between the high resistivity regions and the current apertures among the first III-V layers align with each other. The gate electrode aligns with the current aperture.

In one embodiment, a method of forming a semiconductor device can comprise; forming a HEM device on a semiconductor substrate. The semiconductor substrate provides a current carrying electrode for the semiconductor device and one or more internal conductor structures provide a vertical current path between the semiconductor substrate and regions of the HEM device.

Device architectures based on trapping and de-trapping holes or electrons and/or recombination of both types of carriers are obtained by carrier trapping either in near-interface deep ambipolar states or in quantum wells/dots, either serving as ambipolar traps in semiconductor layers or in gate dielectric/barrier layers. In either case, the potential barrier for trapping is small and retention is provided by carrier confinement in the deep trap states and/or quantum wells/dots. The device architectures are usable as three terminal or two terminal devices.

A semiconductor structure including a first epitaxial region, a second epitaxial region, a gate structure, a source region, a source electrode and a drain electrode. The second epitaxial region is disposed on the first epitaxial region. The gate structure is disposed on the second epitaxial region. The source region is disposed on the second epitaxial region and adjacent to the gate structure. The source electrode is disposed on the source region and is electrically connected to the source region. The drain electrode is disposed on the first epitaxial region and is electrically connected to the first epitaxial region. The first epitaxial region includes an impurity region on a side away from the second epitaxial region, and a concentration of impurities included in the impurity region increases with approaching the second epitaxial region.

A nitride semiconductor device includes: a substrate; an n-type drift layer; a p-type blocking layer; a gate opening which penetrates through the blocking layer to the drift layer; an electron transport layer and an electron supply layer provided on an inner face of the gate opening; a gate electrode above the electron supply layer and covering the gate opening; a source opening penetrating through the electron supply layer and the electron transport layer to the blocking layer; a source electrode covering the source opening, the source electrode being connected to the electron supply layer, the electron transport layer, and the blocking layer; and a drain electrode on a side of the substrate opposite from a side on which the blocking layer is located. A bottom face of the gate electrode is closer to the drain electrode than a bottom face of the blocking layer is.