A transistor structure, includes a buffer layer and a quantum well channel layer on top of the buffer layer. There is a barrier layer on top of the channel layer. There is a drain contact on a channel stack. A source contact is on a channel stack. A gate structure is located between the source contact and drain contact, comprising: an active gate portion having a bottom surface in contact with a bottom surface of the source and the drain contacts. A superconducting portion of the gate structure is in contact with, and adjacent to, an upper part of the active gate portion.

A field effect transistor including a dielectric layer on a substrate, a nano-structure material (NSM) layer on the dielectric layer, a source electrode and a drain electrode formed on the NSM layer, a gate dielectric formed on at least a portion of the NSM layer between the source electrode and the drain electrode, a T-shaped gate electrode formed between the source electrode and the drain electrode, where the NSM layer forms a channel of the FET, and a doping layer on the NSM layer extending at least from the sidewall of the source electrode to a first sidewall of the gate dielectric, and from a sidewall of the drain electrode to a second sidewall of the gate dielectric.

The present description concerns a method of manufacturing a semiconductor component (170), including the successive steps of: providing a stack including a first semiconductor layer (105) made of a III-N compound and a second conductive layer (107) coating the first layer; forming a trench (110) crossing the second layer (107) and stopping on the first layer (105), said trench laterally delimiting a contact metallization in the second layer (107); forming in said trench (110) a metal spacer (111) made of a material different from that of the second layer (107), in contact with the sides of the contact metallization; and continuing said trench (110) through at least a portion of the thickness of the first layer (105).

A high-frequency conductor having improved conductivity comprises at least one electrically conductive base material. The ratio of the outer and inner surfaces of the base material permeable by a current to the total volume of the base material is increased by a) dividing the base material perpendicularly to the direction of current into at least two segments, which are spaced from each other by an electrically conductive intermediate piece and connected both electrically and mechanically to each other, and/or b) topographical structures in or on the surface of the base material and/or c) inner porosity of at least a portion of the base material compared to a design of the base material in which the respective feature was omitted. It was found that, as a result of these measures concerning the design, it is possible to physically arrange the same amount abase material so that a larger fraction of the base material is located at a distance of no more than skin depth from an outer or inner surface and is thus involved in current transport. As a result, a lesser fraction remains unused as a function of the skin effect.

A Field Effect Transistor (FET) structure having: a semiconductor; a first electrode structure; a second electrode structure; and a third electrode structure for controlling a flow of carriers in the semiconductor between the first electrode structure and the second electrode structure; a dielectric structure disposed over the semiconductor and extending horizontally between first electrode structure, the second electrode structure and the third electrode structure; and a fourth electrode passing into the dielectric structure and terminating a predetermined, finite distance above the semiconductor for controlling an electric field in the semiconductor under the fourth electrode structure.

A technique of improving the breakdown voltage of a semiconductor device is provided. There is provided a method of manufacturing a semiconductor device comprising a process of forming a p-type semiconductor layer that contains a p-type impurity and has a dislocation density of not higher than 1.0×10.sup.7 cm.sup.−2, on an n-type semiconductor layer that contains an n-type impurity and has a dislocation density of not higher than 1.0×10.sup.7 cm.sup.−2; an n-type semiconductor region forming process of forming an n-type semiconductor region in at least part of the p-type semiconductor layer by ion-implanting an n-type impurity into the p-type semiconductor layer and performing heat treatment to activate the ion-implanted n-type impurity; and a process of forming a trench that is recessed to pass through the p-type semiconductor layer and reach the n-type semiconductor layer. In the n-type semiconductor region forming process, a p-type impurity diffusion region in which the p-type impurity contained in the p-type semiconductor layer is diffused is formed in at least part of the n-type semiconductor layer that is located below the n-type semiconductor region.

In a high electron mobility transistor (HEMT), dielectric material may be included between edge portions of a HEMT gate and gate field plates in contact with a HEMT gate electrode. At least some portions of the HEMT gate and HEMT gate electrode remain in direct contact with one another, and the HEMT gate electrode and gate field plates may be further connected to a gate metal.

A method for fabricating a semiconductor device includes: forming a silicon nitride film having a refractive index equal to or larger than 2.2 on a nitride semiconductor layer; and introducing at least one of elements that are oxygen, nitrogen, fluorine, phosphorus, sulfur and selenium into the silicon nitride film, the silicon nitride film including the at least one of elements remaining on the nitride semiconductor layer. The at least one of elements is introduced by a process of exposing the silicon nitride film to plasma including the at least one of elements, a process of ion-implanting the at least one of elements into the silicon nitride film, or a process of thermally diffusing the at least one of elements into the silicon nitride film. The silicon nitride film is formed in contact with a surface of the nitride semiconductor layer.

A field effect transistor according to the present invention includes a semiconductor layer including a groove, an insulating film formed on an upper surface of the semiconductor layer and having an opening above the groove and a gate electrode buried in the opening to be in contact with side surfaces and a bottom surface of the groove and having parts being in contact with an upper surface of the insulating film on both sides of the opening, wherein the gate electrode has a T-shaped sectional shape in which a width of an upper end is larger than a width of the upper surface of the insulating film.

An embodiment includes a substrate, wherein a portion of the substrate extends upwards forming a fin, a gate dielectric over a top surface and at least portions of sidewalls of the fin, a gate electrode over the gate dielectric, and a contact over and extending into the gate electrode, wherein the contact has a first width above the gate electrode and a second width within the gate electrode, the first width being smaller than the second width.