Some embodiments of the disclosure provide a method for forming a semiconductor device. The method includes: forming a plurality of semiconductor material layers on a doped substrate; removing a part of the plurality of semiconductor material layers to form an exposed doped substrate; and ion implanting a dopant into the exposed doped substrate to form a doped semiconductor structure, where the doped substrate and the doped semiconductor structure have different polarities.

A vapor phase epitaxy method of growing a III-V layer with a doping that changes from a first conductivity type to a second conductivity type on a surface of a substrate or a preceding layer in a reaction chamber from the vapor phase from an epitaxial gas flow comprising a carrier gas, at least one first precursor for an element from main group III, and at least one second precursor for an element from main group V, wherein when a first growth height is reached, a first initial doping level of the first conductivity type is set by means of a ratio of a first mass flow of the first precursor to a second mass flow of the second precursor, then the first initial doping level is reduced to a second initial doping level of the first or low second conductivity type.

A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) intervenes therebetween.

In some examples, a transistor comprises a gallium nitride (GaN) layer; a GaN-based alloy layer having a top side and disposed on the GaN layer, wherein source, drain, and gate contact structures are supported by the GaN layer; and a first doped region positioned in a drain access region and extending from the top side into the GaN layer.

Nitride semiconductor device includes: a substrate; a first nitride semiconductor layer of a first conductivity above the substrate; a second nitride semiconductor layer of a second conductivity different from the first conductivity, above the first nitride semiconductor layer a first opening penetrating through the second nitride semiconductor layer; an electron transport layer and an electron supply layer disposed along inner surfaces of the first opening, in stated sequence from the substrate-side; a gate electrode above the electron supply layer, covering the first opening; a source electrode connected to the electron supply layer and the electron transport layer, at a position separated from the gate electrode; and a drain electrode on a surface of the substrate opposite to a surface on which the first nitride semiconductor layer is disposed. At least part of the second nitride semiconductor layer is fixed to a potential different from a potential of the source electrode.

Devices, systems, methods, computer-implemented methods, apparatus, and/or computer program products that can facilitate a suspended Majorana fermion device comprising an ion implant defined nanorod in a semiconducting device are provided. According to an embodiment, a quantum computing device can comprise a Majorana fermion device coupled to an ion implanted region. The quantum computing device can further comprise an encapsulation film coupled to the ion implanted region and a substrate layer. The encapsulation film suspends the Majorana fermion device in the quantum computing device.

A mesa structure includes a substrate. A mesa protrudes out of the substrate. The mesa includes a slope and a top surface. The slope surrounds the top surface. A lattice damage area is disposed at inner side of the slope. The mesa can optionally further includes an insulating layer covering the lattice damage area. The insulating layer includes an oxide layer or a nitride layer.

A circuit element is formed on a substrate made of a compound semiconductor. A bonding pad is disposed on the circuit element so as to at least partially overlap the circuit element. The bonding pad includes a first metal film and a second metal film formed on the first metal film. A metal material of the second metal film has a higher Young's modulus than a metal material of the first metal film.

Provided is a method for producing a GaN layered substrate, comprising the steps of: subjecting a C-plane sapphire substrate 11 having an off-angle of 0.5° to 5° to a high-temperature nitriding treatment at 800° C. to 1,000° C. to carry out a surface treatment of the C-plane sapphire substrate; carrying out epitaxial growth of GaN on the surface of the surface-treated C-plane sapphire substrate 11 to produce a GaN film carrier having a surface of an N polar face; forming an ion implantation region 13.sub.ion by carrying out ion implantation on the GaN film 13; laminating and joining a support substrate 12 with the GaN film-side surface of the ion-implanted GaN film carrier; and separating at the ion-implanted region 13.sub.ion in the GaN film 13 to transfer a GaN thin film 13a onto the support substrate 12, to produce a GaN layered substrate 10 having, on the support substrate 12, a GaN thin film 13a having a surface of a Ga polar face. A GaN layered substrate having a good crystallinity and a surface of a Ga face is obtained by a single transfer process.

A method of forming an insulating structure of a high electron mobility transistor (HEMT) is provided, the method including: forming a gallium nitride layer, forming an aluminum gallium nitride layer on the gallium nitride layer, performing an ion doping step to dope a plurality of ions in the gallium nitride layer and the aluminum gallium nitride layer, forming an insulating doped region in the gallium nitride layer and the aluminum gallium nitride layer, forming two grooves on both sides of the insulating doped region, and filling an insulating layer in the two grooves and forming two sidewall insulating structures respectively positioned at two sides of the insulating doped region.