In an embodiment, a semiconductor structure includes a support substrate comprising a surface adapted to support epitaxial growth of a Group III nitride, one or more epitaxial Group III nitride layers arranged on the surface and supporting a plurality of transistor devices assembled upon the support substrate, and a test structure formed in a Group III nitride layer. The test structure includes a plurality of trenches configured to provide an optical diffraction grating when illuminated by UV light. The trenches have a parameter corresponding to a parameter of a feature of the transistor devices.

A high electron mobility transistor and a method of manufacturing the same are disclosed. The high electron mobility transistor includes a channel layer, a channel supplying layer causing generation of a two-dimensional electron gas (2DEG) in the channel layer, a source electrode and a drain electrode provided on respective sides of the channel supplying layer, a depletion forming layer provided on the channel supplying layer to form a depletion region in the 2DEG, a gate electrode provided on a portion of the depletion forming layer, and a current limiting layer provided to contact the gate electrode on another portion of the depletion forming layer. The current limiting layer limits a current flow from the gate electrode to the depletion forming layer according to a voltage applied to the gate electrode.

A Schottky barrier device is provided herein that includes a TMD layer on a substrate, a graphene layer on the TMD layer, an electrolyte layer on the TMD layer, and a source gate contact on the electrolyte layer. A drain contact can be provided on the TMD layer and a source contact can be provided on the graphene layer. As ionic gating from the source gate contact and electrolyte layer is used to adjust the Schottky barrier height this Schottky barrier device can be referred to as an ionic control barrier transistor or ionic barristor.

GaN based nanowires are used to grow high quality, discreet base elements with c-plane top surface for fabrication of various semiconductor devices, such as diodes and transistors for power electronics.

An enhancement-mode GaN transistor with reduced gate leakage current between a gate contact and a 2DEG region and a method for manufacturing the same. The enhancement-mode GaN transistor including a GaN layer, a barrier layer disposed on the GaN layer with a 2DEG region formed at an interface between the GaN layer and the barrier layer, and source contact and drain contacts disposed on the barrier layer. The GaN transistor further includes a p-type gate material formed above the barrier layer and between the source and drain contacts and a gate metal disposed on the p-type gate material, with wherein the p-type gate material including comprises a pair of self-aligned ledges that extend toward the source contact and drain contact, respectively.

A complementary metal oxide semiconductor (CMOS)-integrated junction field effect transistor (JFET) has reduced scale and reduced noise. An exemplary JFET has a substrate layer of one dopant type with a gate layer of that dopant type disposed on the substrate, a depletion channel of a second dopant type disposed on the first gate layer, and a second gate layer of the first dopant type disposed on the depletion channel and proximate a surface of the transistor. The second gate layer can separate the depletion channel from the surface, and the depletion channel separates the first gate layer from the second gate layer.

Techniques are disclosed for providing a low resistance self-aligned contacts to devices formed in a semiconductor heterostructure. The techniques can be used, for example, for forming contacts to the gate, source and drain regions of a quantum well transistor fabricated in III-V and SiGe/Ge material systems. Unlike conventional contact process flows which result in a relatively large space between the source/drain contacts to gate, the resulting source and drain contacts provided by the techniques described herein are self-aligned, in that each contact is aligned to the gate electrode and isolated therefrom via spacer material.

High-voltage, gallium-nitride HEMTs are described that are capable of withstanding reverse-bias voltages of at least 900 V and, in some cases, in excess of 2000 V with low reverse-bias leakage current. A HEMT may comprise a lateral geometry having a gate, a thin insulating layer formed beneath the gate, a gate-connected field plate, and a source-connected field plate.

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.

A layout design of a standard cell for a set of masks includes a first gate pad layout pattern, a second gate pad layout pattern immediately adjacent to the first gate pad layout pattern, and a third gate pad layout pattern immediately adjacent to the second gate pad layout pattern. Each gate pad layout pattern has first and second sides extending along a first direction, the second side further along a second direction than the first side. A first gate pad pitch is a distance between first sides of the first and second gate pad layout patterns and has a value different from that of a second gate pad pitch that is a distance between first sides of the second and third gate pad layout patterns. Each gate pad pattern is usable for forming a gate pad surrounding a set of channel structures.