A semiconductor device includes a semiconductor substrate configured to include a channel, a gate supported by the semiconductor substrate to control current flow through the channel, a first dielectric layer supported by the semiconductor substrate and including an opening in which the gate is disposed, and a second dielectric layer disposed between the first dielectric layer and a surface of the semiconductor substrate in a first area over the channel. The gate may be configured to include a lateral overhang that is separated from an upper surface of the first dielectric layer.

A heterojunction structure of semiconductor material, for a high electron mobility transistor includes a substrate, a buffer layer, arranged on the substrate, of a large bandgap semiconductor material, based on a nitride from column III, where the buffer layer is not intentionally doped with n-type carriers, a barrier layer arranged above the buffer layer, of a large bandgap semiconductor material based on a nitride from column III, where the width of the bandgap of the barrier layer is less than the width of the bandgap of the buffer layer. The heterojunction structure additionally comprises an intentionally doped area, of a material based on a nitride from column III identical to the material of the buffer layer, in a plane parallel to the plane of the substrate and a predefined thickness along a direction orthogonal to the plane of the substrate, where the area is comprised in the buffer layer.

A semiconductor device includes a semiconductor substrate configured to include a channel, first and second ohmic contacts supported by the semiconductor substrate, in ohmic contact with the semiconductor substrate, and spaced from one another for current flow between the first and second ohmic contacts through the channel, and first and second dielectric layers supported by the semiconductor substrate. At least one of the first and second ohmic contacts extends through respective openings in the first and second dielectric layers. The second dielectric layer is disposed between the first dielectric layer and a surface of the semiconductor substrate, and the second dielectric layer includes a wet etchable material having an etch selectivity to a dry etchant of the first dielectric layer.

A transistor device includes a gate fin that is a segment of a semiconductor body disposed between a pair of gate trenches formed in an upper surface of the semiconductor body, a plurality of two-dimensional charge carrier gas channels disposed at different vertical depths within the gate fin, source and drain contacts arranged on either side of the gate fin in a current flow direction of the gate fin, the source and drain contacts each being electrically connected to each one of the two-dimensional charge carrier gas channels, and a gate structure that is configured to control a conductive connection between the source and drain contacts. The gate structure includes a region of doped type III-nitride semiconductor material that covers the gate fin and extends into the gate trenches, and a conductive gate electrode formed over the region of doped type III-nitride semiconductor material.

An electronic device can include a lower channel layer, an upper channel layer overlying the lower channel layer and having an opening extending through the upper channel layer. The electronic device can further include an insulator within the opening; and a gate electrode extending into the opening, wherein the insulator is disposed between the gate electrode and the second channel layer. A double channel transistor can include the lower and upper channel layers and the gate electrode. In a further embodiment, a conductive member can be used to electrically short the channel layers near the gate electrode. In an embodiment, the transistor can be enhancement-mode transistor. A process can include forming the insulator such that it is in the form of a sidewall spacer or as an insulating layer along the sidewall and bottom of the opening through the upper channel layer.

A high-electron mobility transistor includes a substrate layer, a first buffer layer provided on the substrate layer, a barrier layer provided on the first buffer layer, a source provided on the barrier layer, a drain provided on the barrier layer, and a gate provided on the barrier layer. The transistor further includes a p-type material layer having a length parallel to a surface of the substrate layer over which the first buffer layer is provided, the length of the p-type material layer being less than an entire length of the substrate layer. The p-type material layer is provided in one of the following: the substrate layer, or the first buffer layer. A process of making the high-electron mobility transistor is disclosed as well.

An SRAM includes a substrate containing a plurality of first substrate regions and a plurality of second substrate regions, a plurality of pull-down transistors formed in the first substrate regions with each pull-down transistor including a first gate structure, and a plurality of pass-gate transistors formed in the second substrate regions with each pass-gate transistor including a second gate structure. A portion of the first substrate region under each first gate structure is doped with first doping ions and a portion of the second substrate region under each second gate structure is doped with second doping ions. Moreover, the concentration of the first doping ions is less than the concentration of the second doping ions, and the work function of the first work function layer in the first gate structures is greater than the work function of the second work function layer in the second gate structures.

In a semiconductor device in the present disclosure, a first nitride semiconductor layer has a two-dimensional electron gas channel in a vicinity of an interface with a second nitride semiconductor layer. In plan view, an electrode portion is provided between a first electrode and a second electrode with a space between the first electrode and the second electrode, and a space between the second electrode and the electrode portion is smaller than the space between the first electrode and the electrode portion. An energy barrier is provided in a junction surface between the electrode portion and the second nitride semiconductor layer, the energy barrier indicating a rectifying action in a forward direction from the electrode portion to the second nitride semiconductor layer, and a bandgap of the second nitride semiconductor layer is wider than a bandgap of the first nitride semiconductor layer.

A high electron mobility transistor having a channel layer, electron supply layer, source electrode, and drain electrode is included so as to have a cap layer formed on the electron supply layer between the source and drain electrodes and having an inclined side surface, an insulating film having an opening portion on the upper surface of the cap layer and covering the side surface thereof, and a gate electrode is formed in the opening portion and extending, via the insulating film, over the side surface of the cap layer on the drain electrode side. The gate electrode having an overhang on the drain electrode side can reduce the peak electric field.

Methods of manufacturing device assemblies, as well as associated semiconductor assemblies, devices, systems are disclosed herein. In one embodiment, a method of forming a semiconductor device assembly includes forming a semiconductor device assembly that includes a handle substrate, a semiconductor structure having a first side and a second side opposite the first side, and an intermediary material between the semiconductor structure and the handle substrate. The method also includes removing material from the semiconductor structure to form an opening extending from the first side of the semiconductor structure to at least the intermediary material at the second side of the semiconductor structure. The method further includes removing at least a portion of the intermediary material through the opening in the semiconductor structure to undercut the second side of the semiconductor structure.