A nitride semiconductor device includes a substrate, a first electron transport layer above the substrate, a first electron supply layer above the first electron transport layer, a first nitride semiconductor layer above the first electron supply layer, a first opening passing through the first nitride semiconductor layer and the first electron supply layer and reaching the first electron transport layer, a second electron transport layer disposed above the first nitride semiconductor layer and along the inner surface of the first opening, a second electron supply layer disposed above the second electron transport layer and covering the first opening, a gate electrode disposed above the second electron supply layer and covering the first opening, a source electrode connected to the first nitride semiconductor layer and the second electron transport layer, and a drain electrode.

A semiconductor device includes a plurality of column portions including a semiconductor. The plurality of column portions each includes a source region, a drain region, and a channel formation region including a channel formed between the source region and the drain region. The semiconductor device further includes a gate electrode provided, via an insulating layer, at a side wall of the channel formation region, and also includes a first semiconductor layer provided at a side wall of the drain region. A conductive type of the first semiconductor layer differs from a conductive type of the semiconductor included in the drain region.

A vertical type transistor includes: a substrate; a first source/drain electrode layer provided on the substrate; a second source/drain electrode layer provided above the first source/drain electrode layer; a first gate electrode layer provided between the first and second source/drain electrode layers; a first gate insulating film passing through the first gate electrode layer; a hole passing through the second source/drain electrode layer, the first gate insulating film, and the first source/drain electrode layer; and a first channel layer provided on a lateral side of the hole, wherein the first channel layer may include a 2D semiconductor.

Embodiments of the present disclosure include techniques related to techniques for processing materials for manufacture of group-III metal nitride and gallium based substrates. More specifically, embodiments of the disclosure include techniques for growing large area substrates using a combination of processing techniques. Merely by way of example, the disclosure can be applied to growing crystals of GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, and others for manufacture of bulk or patterned substrates. Such bulk or patterned substrates can be used for a variety of applications including optoelectronic and electronic devices, lasers, light emitting diodes, solar cells, photo electrochemical water splitting and hydrogen generation, photodetectors, integrated circuits, and transistors, and others.

A MOSFET with saturation contact. The MOSFET with saturation contact includes an n-doped source region, a source contact, a contact structure, which extends from the source contact to the n-doped source region, and forms with the source contact a first conductive connection and forms with the n-doped source region a second conductive connection, a barrier layer and an insulating layer. The contact structure includes a section between the first conductive connection and the second conductive connection, which is embedded between the barrier layer and the dielectric layer and is configured in such a way that a two-dimensional electron gas is formed therein.

The present invention provides a field effect transistor device and a method for improving the short-channel effect and the output characteristics using the same. The field effect transistor device comprises an active layer comprising a source region, a drain region, and a channel region located between the source region and the drain region; when the device is turned on, an effective channel and an equivalent source and/or equivalent drain away from the effective channel are formed in the channel region, and the field effect transistor device connects the source region with the drain region through the effective channel, and the equivalent source and/or equivalent drain to form an operating current.

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 nitride semiconductor device includes a substrate, a drift layer and a block layer sequentially provided above the substrate, a gate opening penetrating through a block layer and reaching a drift layer, an electron transit layer and an electron supply layer sequentially provided above the block layer and along the inner surface of the gate opening, a gate electrode provided to cover the gate opening, a source opening penetrating through an electron supply layer and an electron transit layer and reaching the block layer, a source electrode provided in the source opening, and a drain electrode on the rear surface side of the substrate. Seen in a plan view, at least part of an outline of an end of the gate opening in the longitudinal direction follows an arc or an elliptical arc.

A compound semiconductor has a high electron concentration of 5×10.sup.19 cm.sup.−3 or higher, exhibits an electron mobility of 46 cm.sup.2/V.Math.s or higher, and exhibits a low electric resistance, and thus is usable to produce a high performance semiconductor device. The present invention provides a group 13 nitride semiconductor of n-type conductivity that may be formed as a film on a substrate having a large area size at a temperature of room temperature to 700° C.

Embodiments are directed to high electron mobility transistor (HEMT) devices and methods. One such HEMT device includes a substrate having a first surface, and first and second heterostructures on the substrate and facing each other. Each of the first and second heterostructures includes a first semiconductor layer on the first surface of the substrate, a second semiconductor layer on the first surface of the substrate, and a two-dimensional electrode gas (2DEG) layer between the first and second semiconductor layers. A doped semiconductor layer is disposed between the first and second heterostructures, and a source contact is disposed on the first heterostructure and the second heterostructure.