A Group III-Nitride quantum well laser including a distributed Bragg reflector (DBR). In some embodiments, the DBR includes Scandium. In some embodiments, the DBR includes Al.sub.1-xSc.sub.xN, which may have 0<x≤0.45.

An electronic circuit having a semiconductor device is provided that includes a heterostructure, the heterostructure including a first layer of a compound semiconductor to which a second layer of a compound semiconductor adjoins in order to form a channel for a 2-dimensional electron gas (2DEG), wherein the 2-dimensional electron gas is not present. In aspects, an electronic circuit having a semiconductor device is provided that includes a III-V heterostructure, the III-V heterostructure including a first layer including GaN to which a second layer adjoins in order to form a channel for a 2-dimensional electron gas (2DEG), and having a purity such that the 2-dimensional electron gas is not present. It is therefore advantageous for the present electronic circuit to be enclosed such that, in operation, no light of wavelengths of less than 400 nm may reach the III-V heterostructure and free charge carriers may be generated by these wavelengths.

A stacked, high-blocking III-V semiconductor power diode having a first metallic terminal contact layer, formed at least in regions, and a highly doped semiconductor contact region of a first conductivity type and a first lattice constant. A drift layer of a second conductivity type and having a first lattice constant is furthermore provided. A semiconductor contact layer of a second conductivity, which includes an upper side and an underside, and a second metallic terminal contact layer are formed, and the second metallic terminal contact layer being integrally connected to the underside of the semiconductor contact layer, and the semiconductor contact layer having a second lattice constant at least on the underside, and the second lattice constant being the lattice constant of InP, and the drift layer and the highly doped semiconductor contact region each comprising an InGaAs compound or being made up of InGaAs.

A stacked, high-blocking III-V semiconductor power diode having a first metallic terminal contact layer, formed at least in regions, and a highly doped semiconductor contact region of a first conductivity type and a first lattice constant. A drift layer of a second conductivity type and having a first lattice constant is furthermore provided. A semiconductor contact layer of a second conductivity, which includes an upper side and an underside, and a second metallic terminal contact layer are formed, and the second metallic terminal contact layer being integrally connected to the underside of the semiconductor contact layer, and the semiconductor contact layer having a second lattice constant at least on the underside, and the second lattice constant being the lattice constant of InP, and the drift layer and the highly doped semiconductor contact region each comprising an InGaAs compound or being made up of InGaAs.

A high electron mobility transistor includes: a first semiconductor layer over a substrate, and a second semiconductor layer over the first semiconductor layer, the second semiconductor layer having a band gap discontinuity with the first semiconductor layer, and at the first semiconductor layer and/or the second conductive layer includes indium. A top layer is over the second semiconductor layer, and a metal layer is over, and extends into, the top layer, the top layer separating the metal layer from the second semiconductor layer. A gate electrode is over the top layer, a third semiconductor layer being between the gate electrode and the top layer, where a sidewall of the third semiconductor layer and a sidewall of the metal layer are separated. A source and drain are on opposite sides of the gate electrode, the top layer extending continuously from below the source, below the gate electrode, and below the drain.

A high-electron mobility transistor includes a substrate; a channel layer on the substrate; a AlGaN layer on the channel layer; and a P—GaN gate on the AlGaN layer. The AlGaN layer comprises a first region and a second region. The first region has a composition that is different from that of the second region.

A semiconductor structure includes: a channel layer; an active layer over the channel layer, wherein the active layer is configured to form a two-dimensional electron gas (2DEG) to be formed in the channel layer along an interface between the channel layer and the active layer; a gate electrode over a top surface of the active layer; and a source/drain electrode over the top surface of the active layer; wherein the active layer includes a first layer and a second layer sequentially disposed therein from the top surface to a bottom surface of the active layer, and the first layer possesses a higher aluminum (Al) atom concentration compared to the second layer. An HEMT structure and an associated method are also disclosed.

A semiconductor structure includes: a channel layer; an active layer over the channel layer, wherein the active layer is configured to form a two-dimensional electron gas (2DEG) to be formed in the channel layer along an interface between the channel layer and the active layer; a gate electrode over a top surface of the active layer; and a source/drain electrode over the top surface of the active layer; wherein the active layer includes a first layer and a second layer sequentially disposed therein from the top surface to a bottom surface of the active layer, and the first layer possesses a higher aluminum (Al) atom concentration compared to the second layer. An HEMT structure and an associated method are also disclosed.

A buffer layer formed on a substrate, a base layer formed on the buffer layer, and a channel layer formed on the base layer are provided. The base layer includes Al.sub.xGa.sub.1-xN(0<x≤1) and the composition x of Al decreases in accordance with increasing approach of the composition x to the channel layer in a thickness direction. The channel layer includes Al.sub.yGa.sub.1-yN(0<y≤1) and the composition y of Al decreases in accordance with increasing approach of the composition y to the base layer in a thickness direction.

A double Schottky-barrier diode includes a semi-insulating substrate, a left mesa formed by growth and etching on the semi-insulating substrate, a middle mesa formed by growth and etching on the semi-insulating substrate, a right mesa formed by growth and etching on the semi-insulating substrate, two anode probes and two air-bridge fingers. The two Schottky contacts are closely fabricated on the same mesa (middle mesa) in a back-to-back manner to obtain even symmetric C-V characteristics and odd symmetric I-V characteristics from the device level. The output of a frequency multiplier fabricated using the double Schottky-barrier diode only has odd harmonics, but no even harmonics, which is suitable for the production of high-order frequency multipliers. The cathodes of the two Schottky contacts are connected by the buffer layer without ohmic contact.