An epitaxial wafer according to the present disclosure includes: a substrate; a buffer layer formed of a crystal having the composition formula represented by Al.sub.xGa.sub.yIn.sub.zN (x+y+z=1, y>0) on the substrate; a back-barrier layer formed of a crystal having the composition formula represented by Al.sub.xGa.sub.yIn.sub.zN (x+y+z=1, y>0, z>0) on the buffer layer; a channel layer formed of a crystal having the composition formula represented by Al.sub.xGa.sub.yIn.sub.zN (x+y+z=1, y>0) on the back-barrier layer; and an electron-supply layer formed of a crystal having the composition formula represented by Al.sub.xGa.sub.yIn.sub.zN (x+y+z=1, x>0) on the channel layer. The channel layer is constituted with an upper channel layer underneath the electron-supply layer and a lower channel layer on the back-barrier layer, and the lower channel layer has a C concentration higher than the upper channel layer and contains Si.

A semiconductor transistor structure with reduced contact resistance includes a substrate, a channel layer on the substrate, a barrier layer on the channel layer, a two-dimensional electron gas (2DEG) layer at an interface between the barrier layer and the channel layer, and a recess in a contact region. The recess penetrates through the barrier layer and extends into the channel layer. An Ohmic contact metal is disposed in the recess. The Ohmic contact metal is in direct contact with a vertical side surface of the barrier layer in the recess and in direct contact with an inclined side surface of the 2DEG layer and the channel layer in the recess.

An apparatus configured to reduce lag includes a substrate; a group III-Nitride back barrier layer on the substrate; a group III-Nitride channel layer on the group III-Nitride back barrier layer; a group III-Nitride barrier layer on the group III-Nitride channel layer, the group III-Nitride barrier layer include a higher bandgap than a bandgap of the group III-Nitride channel layer; a source electrically coupled to the group III-Nitride barrier layer; a gate on the group III-Nitride barrier layer; a drain electrically coupled to the group III-Nitride barrier layer; and a p-region being arranged at or below the group III-Nitride barrier layer. Additionally, at least a portion of the p-region is arranged vertically below at least one of the following: the source, the gate, an area between the gate and the drain.

An apparatus includes a substrate; a group III-Nitride barrier layer; a source electrically coupled to the group III-Nitride barrier layer; a gate on the group III-Nitride barrier layer; a drain electrically coupled to the group III-Nitride barrier layer; a p-region being arranged at or below the group III-Nitride barrier layer; and a recovery enhancement circuit configured to reduce an impact of an overload received by the gate. Additionally, at least a portion of the p-region is arranged vertically below at least one of the following: the source, the gate, an area between the gate and the drain.

Disclosed herein are IC structures, packages, and devices that include III-N transistors integrated on the same substrate or die as resonators of RF filters. An example IC structure includes a support structure (e.g., a substrate), a resonator, provided over a first portion of the support structure, and an III-N transistor, provided over a second portion of the support structure. The IC structure includes a piezoelectric material so that first and second electrodes of the resonator enclose a first portion of the piezoelectric material, while a second portion of the piezoelectric material is enclosed between the channel material of the III-N transistor and the support structure. In this manner, one or more resonators of an RF filter may be monolithically integrated with one or more III-N transistors. Such integration may reduce costs and improve performance by reducing RF losses incurred when power is routed off chip.

Various embodiments of the present disclosure are directed towards an integrated chip a first undoped layer overlies a substrate. A first barrier layer overlies the first undoped layer and has a first thickness. A first doped layer overlies the first barrier layer and is disposed laterally within an n-channel device region of the substrate. A second barrier layer overlies the first barrier layer and is disposed within a p-channel device region that is laterally adjacent to the n-channel device region. The second barrier layer has a second thickness that is greater than the first thickness. A second undoped layer overlies the second barrier layer. A second doped layer overlies the second undoped layer. The second undoped layer and the second doped layer are disposed within the p-channel device region.

One or more semiconductor structures comprising a hole draining structure are provided. A semiconductor structure has a first layer formed over a substrate. The first layer has a first concentration of a metal material. The semiconductor structure has a second layer formed over the first layer. The second layer has a second concentration of the metal material different than the first concentration of the metal material. The semiconductor structure has a hole draining structure formed from a superlattice formed between the first layer and the second layer. The hole draining structure has a concentration of the metal material increasing towards the first layer and decreasing towards the second layer.

Methods for inducing reversible or permanent conductivity in wide band gap metal oxides such as Ga.sub.2O.sub.3, using light without doping, as well as related compositions and devices, are described.

A high electron mobility transistor comprising a nucleation layer having a first lattice constant, a back-barrier layer having a second lattice constant and a stress management layer having a third lattice constant which is larger than both first and second lattice constants. The stress management layer compensates some or all of the stress due to the lattice mismatch between the nucleation layer and back barrier layer so that the resulting structure experiences less bow and warp.

A semiconductor device includes a first and a second nitride-based semiconductor layers, a source electrode, a drain electrode, a gate electrode, and a first and a second stress modulation layers. The first nitride-based semiconductor layer has a first thickness. The second nitride-based semiconductor layer has a bandgap less than a bandgap of the first nitride-based semiconductor layer to form a heterojunction therebetween. The second nitride-based semiconductor layer has a second thickness, and a ratio of the first thickness to the second thickness is in a range from 0.5 to 5. The first and the second stress modulation layers provide a first and a second drift regions of the second nitride-based semiconductor layer with stress, respectively, resulting in induction of a first and a second 2DHG regions within the first and the second drift regions, respectively.