Thin film transistors (TFTs), including radiofrequency TFTs, with submicron-scale channel lengths and methods for making the TFTs are provided. The transistors include a trench cut into the layer of semiconductor that makes up the body of the transistors. Trench separates the source and drain regions and determines the channel length of the transistor.

The invention relates to a method for fabricating a semiconductor circuit comprising providing a semiconductor substrate; fabricating a first semiconductor device comprising a first semiconductor material on the substrate and forming an insulating layer comprising a cavity structure on the first semiconductor device. The cavity structure comprises at least one growth channel and the growth channel connects a crystalline seed surface of the first semiconductor device with an opening. Further steps include growing via the opening from the seed surface a semiconductor filling structure comprising a second semiconductor material different from the first semiconductor material in the growth channel; forming a semiconductor starting structure for a second semiconductor device from the filling structure; and fabricating a second semiconductor device comprising the starting structure. The invention is notably also directed to corresponding semiconductor circuits.

An electrical device comprising a base semiconductor layer of a silicon including material; a dielectric layer present on the base semiconductor layer; a first III-V semiconductor material area present in a trench in the dielectric layer, wherein a via of the III-V semiconductor material extends from the trench through the dielectric layer into contact with the base semiconductor layer; a second III-V semiconductor material area present in the trench in the dielectric layer wherein the second III-V semiconductor material area does not have a via extending through the dielectric layer into contact with the base semiconductor layer; and a semiconductor device present on the second III-V semiconductor material area, wherein the first III-V semiconductor material area and the second III-V semiconductor material area are separated by a low aspect ratio trench extending to the dielectric layer.

Semiconductor devices having group III-V material active regions and graded gate dielectrics and methods of fabricating such devices are described. In an example, a semiconductor device includes a group III-V material channel region disposed above a substrate. A gate stack is disposed on the group III-V material channel region. The gate stack includes a graded high-k gate dielectric layer disposed directly between the III-V material channel region and a gate electrode. The graded high-k gate dielectric layer has a lower dielectric constant proximate the III-V material channel region and has a higher dielectric constant proximate the gate electrode. Source/drain regions are disposed on either side of the gate stack.

The present disclosure relates to semiconductor structures and, more particularly, to a symmetric tunnel field effect transistor and methods of manufacture. The structure includes a gate structure including a source region and a drain region both of which comprise a doped VO.sub.2 region.

A semiconductor device and a method of making the same. The device includes a substrate having an AlGaN layer located on one or more GaN layers, for forming a two dimensional electron gas at an interface between the AlGaN layer and the GaN layer. The device also includes a source contact. The device further includes a drain contact. The device also includes a gate contact located between the source contact and the drain contact. The gate contact includes a gate electrode. The gate contact also includes an electrically insulating layer located between the gate electrode and the AlGaN layer. The insulating layer includes at least one aperture for allowing holes generated during an off-state of the device to exit the device through the gate electrode.

Deep gate-all-around semiconductor devices having germanium or group III-V active layers are described. For example, a non-planar semiconductor device includes a hetero-structure disposed above a substrate. The hetero-structure includes a hetero-junction between an upper layer and a lower layer of differing composition. An active layer is disposed above the hetero-structure and has a composition different from the upper and lower layers of the hetero-structure. A gate electrode stack is disposed on and completely surrounds a channel region of the active layer, and is disposed in a trench in the upper layer and at least partially in the lower layer of the hetero-structure. Source and drain regions are disposed in the active layer and in the upper layer, but not in the lower layer, on either side of the gate electrode stack.

A method of forming a thin film includes: (1) providing an ink composition including nanoplates of a layered material disposed in a liquid dispersion medium; (2) applying the ink composition over a substrate to form a coating; and (3) annealing the coating to form a thin film of the nanoplates over the substrate.

A transistor based on topological insulators is provided. In an embodiment a topological insulator is used to form both the channel as well as the source/drain regions, wherein the channel has a first thickness such that the topological insulator material has properties of a semiconductor material and the source/drain regions have a second thickness such that the topological insulator has properties of a conductive material.

A Schottky barrier semiconductor device having a nanoscale film interface comprises a Schottky barrier layer and a metal electrode; wherein a nanoscale film interface layer is formed on a top surface of the Schottky barrier layer, a thickness of the nanoscale film interface layer is greater than 3 and smaller than 20 , the nanoscale film interface layer is made of at least one oxide; the metal electrode is formed on the nanoscale film interface layer and contacted with the nanoscale film interface layer.