Described herein are lateral III-N (e.g., GaN) devices having a III-N depleting layer. A circuit includes a depletion-mode transistor with a source connected to a drain of an enhancement-mode transistor. The gate of the depletion-mode transistor and the gate of the enhancement-mode transistor are biased at zero volts, and the drain of the depletion-mode transistor is biased at positive voltage to block a current in a forward direction. Then, the bias of the gate of the enhancement-mode transistor is changed to a first voltage greater than the threshold voltage of the enhancement-mode transistor and a first current is allowed to flow through the channel in a forward direction. Then, the bias of the gate of the depletion-mode transistor is changed to a second voltage and a second current is allowed to flow through the channel in a forward direction where the second current is greater than the first current.

Various techniques for impurity dopant reduction in GaN regrowth are described. In a first technique, a barrier layer, such as AlN, can be formed at a regrowth interface before the regrown GaN layer. The barrier layer can bury the impurities at the regrowth interface and reduce their effect on the layers above that include the channel of the device, e.g., transistor. In a second technique, a buffer layer, such as a carbon-doped GaN layer, can be formed at the regrowth interface before the regrown GaN layer. Carbon can act as an acceptor to compensate for the dopants. e.g., silicon, and cancel their electronic effect on the above layers. In a third technique, a hydrogen bake treatment can be performed before the GaN regrowth. Hydrogen can desorb a thin layer of GaN at the regrowth interface, which is the GaN layer with the highest concentration of impurities.

Various embodiments of the present disclosure are directed towards an integrated chip including a first semiconductor layer overlying a substrate. A first barrier layer is disposed on the first semiconductor layer. A second semiconductor layer overlies and directly contacts the first barrier layer. A second barrier layer directly contacts the first barrier layer. A third semiconductor layer overlies the second barrier layer. A fourth semiconductor layer overlies the third semiconductor layer. Outer sidewalls of the third semiconductor layer, outer sidewalls of the fourth semiconductor layer, and outer sidewalls of the second barrier layer are respectively aligned.

A semiconductor device includes a nucleation layer, a buffer layer, a first nitride-based semiconductor layer, a second nitride-based semiconductor layer, S/D electrodes, and a gate electrode. The nucleation layer includes a composition that includes a first element. The buffer layer includes a III-V compound which includes the first element. The buffer layer is disposed on and forms an interface with the nucleation layer. The buffer layer has a concentration of the first element oscillating within the buffer layer, such that the concentration of the first element varies as an oscillating function of a distance within a thickness of the buffer layer. Spacings among adjacent peaks of the oscillating function change from narrow to wide with respect to a first reference point within the buffer layer. The first and second nitride-based semiconductor layer, S/D electrodes, and a gate electrode are disposed on the buffer layer.

Apparatuses and methods relating to semiconductor layer structures are disclosed. A method for producing a semiconductor layer structure ay involve providing a Si substrate comprising a top surface, forming a first semiconductor layer on the substrate, the first semiconductor layer comprising a plurality of vertical nanowire structures, arranged perpendicularly to the top surface of the substrate, the first semiconductor layer comprising AlN, and epitaxially growing a second semiconductor layer which laterally and vertically encloses the plurality of vertical nanowire structures thereby encapsulating dislocations in shells around the nanowires, wherein the second semiconductor layer comprises Al.sub.xGa.sub.1-xN, wherein 0x0.95.

Embodiments include epitaxial semiconductor stacks for reduced defect densities in III-N device layers grown over non-III-N substrates, such as silicon substrates. In embodiments, a metamorphic buffer includes an Al.sub.xIn.sub.1-xN layer lattice matched to an overlying GaN device layers to reduce thermal mismatch induced defects. Such crystalline epitaxial semiconductor stacks may be device layers for HEMT or LED fabrication, for example. System on Chip (SoC) solutions integrating an RFIC with a PMIC using a transistor technology based on group III-nitrides (III-N) capable of achieving high F.sub.t and also sufficiently high breakdown voltage (BV) to implement high voltage and/or high power circuits may be provided on the semiconductor stacks in a first area of the silicon substrate while silicon-based CMOS circuitry is provided in a second area of the substrate.

A semiconductor device includes a semiconductor structure forming a carrier channel, a barrier layer arranged in proximity with the semiconductor structure, and a set of electrodes for providing and controlling carrier charge in the carrier channel. The barrier layer is at least partially doped by impurities having a conductivity type opposite to a conductivity type of the carrier channel. The material of the barrier layer has a bandgap and thermal conductivity larger than a bandgap and thermal conductivity of material in the semiconductor structure.

The semiconductor device includes a trench that penetrates a barrier layer, and reaches a middle portion of a channel layer among an n+ layer, an n-type layer, a p-type layer, the channel layer, and the barrier layer which are formed above a substrate, a gate electrode arranged within the groove through a gate insulating film, and a source electrode and a drain electrode which are formed above the barrier layer on both sides of the gate electrode. The n-type layer and the drain electrode are electrically coupled by a connection portion that reaches the n+ layer. The p-type layer and the source electrode are electrically coupled by a connection portion that reaches the p-type layer. A diode including a p-type layer and an n-type layer is provided between the source electrode and the drain electrode, to thereby prevent the breaking of an element caused by an avalanche breakdown.

A semiconductor device includes a buffer layer, a channel layer, a barrier layer, and agate electrode over a substrate, the gate electrode being disposed in a first opening with agate insulating film in between, the first opening running up to the middle of the channel layer through the barrier layer. The concentration of two-dimensional electron gas in a first region on either side of a second opening that will have a channel is controlled to be lower than the concentration of two-dimensional electron gas in a second region between an end of the first region and a source or drain electrode. The concentration of the two-dimensional electron gas in the first region is thus decreased, thereby the conduction band-raising effect of polarization charge is prevented from being reduced. This prevents a decrease in threshold potential, and thus improves normally-off operability.

The characteristics of a semiconductor device are improved. A semiconductor device has an impurity-containing potential fixed layer, and a gate electrode. A drain electrode and a source electrode are formed on the opposite sides of the gate electrode. An interlayer insulation film is formed between the gate electrode and the drain electrode, and between the gate electrode and the source electrode. The concentration of the inactivating element in the portion of the potential fixed layer under the drain electrode is higher than the concentration of the inactivating element in the portion of the potential fixed layer under the source electrode. The film thickness of the portion of the interlayer insulation film between the gate electrode and the drain electrode is different from the film thickness of the portion of the interlayer insulation film between the gate electrode and the source electrode.