Abstract: A strain compensated heterostructure comprising a substrate comprising silicon carbide material; a first epitaxial layer comprising single-crystal aluminum nitride material formed on a top surface of the substrate; a second epitaxial layer formed on the first epitaxial layer opposite the top surface of the substrate, the second epitaxial layer comprising single-crystal scandium aluminum nitride material; and a third epitaxial layer formed on the second epitaxial layer opposite the first epitaxial layer, the third layer comprising single-crystal aluminum nitride material.

Abstract: An Enhancement-Mode HEMT having a gate electrode with a doped, Group III-N material disposed between an electrically conductive gate electrode contact and a gate region of the Enhancement-Mode HEMT, such doped, Group III-N layer increasing resistivity of the Group III-N material to deplete the 2DEG under the gate at zero bias.

Abstract: A High Electron Mobility Transistor structure having: a GaN buffer layer disposed on the substrate; a doped GaN layer disposed on, and in direct contact with, the buffer layer, such doped GaN layer being doped with more than one different dopants; an unintentionally doped (UID) GaN channel layer on, and in direct contact with, the doped GaN layer, such UID GaN channel layer having a 2DEG channel therein; a barrier layer on, and in direct contact with, the UID GaN channel layer. One of the dopants is beryllium and another one of the dopants is carbon.

Abstract: A strain compensated heterostructure comprising a substrate comprising silicon carbide material; a first epitaxial layer comprising single-crystal aluminum nitride material formed on a top surface of the substrate; a second epitaxial layer formed on the first epitaxial layer opposite the top surface of the substrate, the second epitaxial layer comprising single-crystal scandium aluminum nitride material; and a third epitaxial layer formed on the second epitaxial layer opposite the first epitaxial layer, the third layer comprising single-crystal aluminum nitride material.

Abstract: A semiconductor device having a substrate, a pair of Group III-Nitride layers on the substrate forming: a heterojunction with a 2 Dimensional Electron Gas (2DEG) channel in a lower one of the pair of Group III-Nitride layers, a cap beryllium doped Group III-Nitride layer on the upper one of the pair of Group III-Nitride layers; and an electrical contact in Schottky contact with a portion of the cap beryllium doped, Group III-Nitride layer.

Abstract: A semiconductor device having a substrate, a pair of Group III-Nitride layers on the substrate forming: a heterojunction with a 2 Dimensional Electron Gas (2DEG) channel in a lower one of the pair of Group III-Nitride layers, a cap beryllium doped Group III-Nitride layer on the upper one of the pair of Group III-Nitride layers; and an electrical contact in Schottky contact with a portion of the cap beryllium doped, Group III-Nitride layer.

Abstract: An Enhancement-Mode HEMT having a gate electrode with a doped, Group III-N material disposed between an electrically conductive gate electrode contact and a gate region of the Enhancement-Mode HEMT, such doped, Group III-N layer increasing resistivity of the Group III-N material to deplete the 2DEG under the gate at zero bias.

Abstract: A method includes providing a single crystal substrate having a buffer layer on a surface of the substrate. The buffer layer provides a transition between the crystallographic lattice structure of the substrate and the crystallographic lattice structure of the semiconductor layer and has its resistivity increased by ion implanting a dopant into the buffer layer; and forming semiconductor layer on the ion implanted buffer layer. The semiconductor layer may be a wide bandgap semiconductor layer having a high electron mobility transistors formed therein.

Abstract: An Enhancement-Mode HEMT having a gate electrode with a doped, Group III-N material disposed between an electrically conductive gate electrode contact and a gate region of the Enhancement-Mode HEMT, such doped, Group III-N layer increasing resistivity of the Group III-N material to deplete the 2DEG under the gate at zero bias.

Abstract: A High Electron Mobility Transistor structure having: a GaN buffer layer disposed on the substrate; a doped GaN layer disposed on, and in direct contact with, the buffer layer, such doped GaN layer being doped with more than one different dopants; an unintentionally doped (UID) GaN channel layer on, and in direct contact with, the doped GaN layer, such UID GaN channel layer having a 2DEG channel therein; a barrier layer on, and in direct contact with, the UID GaN channel layer. One of the dopants is beryllium and another one of the dopants is carbon.

Abstract: A method includes providing a single crystal substrate having a buffer layer on a surface of the substrate. The buffer layer provides a transition between the crystallographic lattice structure of the substrate and the crystallographic lattice structure of the semiconductor layer and has its resistivity increased by ion implanting a dopant into the buffer layer; and forming semiconductor layer on the ion implanted buffer layer. The semiconductor layer may be a wide bandgap semiconductor layer having a high electron mobility transistors formed therein.

Abstract: An Enhancement-Mode HEMT having a gate electrode with a doped, Group III-N material disposed between an electrically conductive gate electrode contact and a gate region of the Enhancement-Mode HEMT, such doped, Group III-N layer increasing resistivity of the Group III-N material to deplete the 2DEG under the gate at zero bias.

Abstract: A structure having: a nucleation layer; and a Group III-Nitride structure disposed on a surface of the nucleation layer, the Group III-Nitride structure comprising a plurality of pairs of stacked Group III-Nitride layers, each one of the pairs of layers having a lower layer having a 3D growth structure and each one of the upper one of the pairs of layers having a 2D growth structure. Each one of the lower layers at completion has a surface roughness greater than a surface roughness at completion of an upper one of the pair of layers. Interfaces between each one of the upper layers and each one of the lower layers of the plurality of pairs of stacked Group III-Nitride layers have crystallographic dislocation combinations and/or annihilations therein.

Abstract: A semiconductor structure having a buffer layer, a pseudomorphic, impurity doped, back-barrier layer disposed on the buffer layer, a channel layer disposed on the back-barrier layer, the channel layer lattice matched to the buffer layer, and a top barrier layer disposed on the channel layer. A Group III-Nitride transition layer is disposed between the buffer layer and the pseudomorphic back-barrier layer. The buffer layer and the pseudomorphic back-barrier layer are both Group III-Nitride materials. The Group III-Nitride material of the buffer layer is different from the Group III-Nitride material in the back-barrier layer. The back-barrier layer has a wider bandgap of than the buffer layer bandgap. The composition of the Group III-Nitride material in the transition layer varies from the composition of the Group III-Nitride material in the buffer layer to the composition of the Group III-Nitride material in the pseudomorphic back-barrier layer as a function of distance from the buffer layer.

Abstract: A structure having: a nucleation layer; and a Group III-Nitride structure disposed on a surface of the nucleation layer, the Group III-Nitride structure comprising a plurality of pairs of stacked Group III-Nitride layers, each one of the pairs of layers having a lower layer having a 3D growth structure and each one of the upper one of the pairs of layers having a 2D growth structure. Each one of the lower layers at completion has a surface roughness greater than a surface roughness at completion of an upper one of the pair of layers. Interfaces between each one of the upper layers and each one of the lower layers of the plurality of pairs of stacked Group III-Nitride layers have crystallographic dislocation combinations and/or annihilations therein.

Abstract: A semiconductor structure having a buffer layer, a pseudomorphic, impurity doped, back-barrier layer disposed on the buffer layer, a channel layer disposed on the back-barrier layer, the channel layer lattice matched to the buffer layer, and a top barrier layer disposed on the channel layer. A Group III-Nitride transition layer is disposed between the buffer layer and the pseudomorphic back-barrier layer. The buffer layer and the pseudomorphic back-barrier layer are both Group III-Nitride materials. The Group III-Nitride material of the buffer layer is different from the Group III-Nitride material in the back-barrier layer. The back-barrier layer has a wider bandgap of than the buffer layer bandgap. The composition of the Group III-Nitride material in the transition layer varies from the composition of the Group III-Nitride material in the buffer layer to the composition of the Group III-Nitride material in the pseudomorphic back-barrier layer as a function of distance from the buffer layer.

Abstract: A semiconductor structure having a buffer layer, a pseudomorphic, impurity doped, back-barrier layer disposed on the buffer layer, a channel layer disposed on the back-barrier layer, the channel layer lattice matched to the buffer layer, and a top barrier layer disposed on the channel layer. A Group III-Nitride transition layer is disposed between the buffer layer and the pseudomorphic back-barrier layer. The buffer layer and the pseudomorphic back-barrier layer are both Group III-Nitride materials. The Group III-Nitride material of the buffer layer is different from the Group III-Nitride material in the back-barrier layer. The back-barrier layer has a wider bandgap of than the buffer layer bandgap. The composition of the Group III-Nitride material in the transition layer varies from the composition of the Group III-Nitride material in the buffer layer to the composition of the Group III-Nitride material in the pseudomorphic back-barrier layer as a function of distance from the buffer layer.

Abstract: A semiconductor structure having a buffer layer, a pseudomorphic, impurity doped, back-barrier layer disposed on the buffer layer, a channel layer disposed on the back-barrier layer, the channel layer lattice matched to the buffer layer, and a top barrier layer disposed on the channel layer. A Group III-Nitride transition layer is disposed between the buffer layer and the pseudomorphic back-barrier layer. The buffer layer and the pseudomorphic back-barrier layer are both Group III-Nitride materials. The Group III-Nitride material of the buffer layer is different from the Group III-Nitride material in the back-barrier layer. The back-barrier layer has a wider bandgap of than the buffer layer bandgap. The composition of the Group III-Nitride material in the transition layer varies from the composition of the Group III-Nitride material in the buffer layer to the composition of the Group III-Nitride material in the pseudomorphic back-barrier layer as a function of distance from the buffer layer.

Abstract: A semiconductor structure having a Group III-N buffer layer and a Group III-N barrier layer in direct contact to form a junction between the Group III-V buffer layer the Group III-N barrier layer producing a two dimensional electron gas (2DEG) channel, the Group III-N barrier layer having a varying dopant concentration. The lower region of the Group III-N barrier layer closest to the junction is void of intentionally introduced dopant and a region above the lower region having intentionally introduced, predetermined dopant with a predetermined doping concentration above 1×1017 atoms per cm3.

Abstract: A plasma generating system. A pair of electrodes are spaced apart by an electrode gap. A source of a gas adapted to place the gas in the electrode gap. A power generating circuit is coupled to the electrodes to generate an electric field across the electrodes so as to initiate a plasma discharge within the electrode gap. The power generating circuit has adequate capacity to maintain a sufficient electric field across the gap during the plasma discharge to allow a plasma impedance to self-tune to the plasma generating system. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.