A device includes a substrate; a buffer layer on the substrate; a barrier layer on the buffer layer, a source electrically coupled to the barrier layer; a gate electrically coupled to the barrier layer; and a drain electrically coupled to the barrier layer. The device further includes an electron concentration reduction structure arranged with at least one of the following: in the barrier layer and on the barrier layer. The electron concentration reduction structure is configured to at least one of the following: reduce electron concentration around the gate, reduce electron concentration around an edge of the gate, reduce electron concentration, increase power gain, increase efficiency, decouple the gate from the drain, decouple the gate from the source, and reduce capacitance.

Methods and systems for selectively depositing material, such as doped semiconductor material, are disclosed. An exemplary method includes providing a substrate, comprising a first area comprising a first material and a second area comprising a second material, selectively depositing a first doped semiconductor layer overlying the first material relative to the second material and selectively depositing a second doped semiconductor layer overlying the first doped semiconductor layer relative to the second material.

A transistor using patterned metamaterial electrode manipulating electromagnetic waves to achieve matched phase velocity on the input and output ports. A design method is taught wherein the layout of the electrodes can be designed to compensate for the phase-velocity mismatch induced by the transistor's intrinsic properties.

An embodiment of a semiconductor device includes a semiconductor substrate, a first dielectric layer, a first current-carrying electrode, and a second current-carrying electrode are formed over the semiconductor substrate. The first current-carrying electrode and the second current-carrying electrode include a first conductive layer formed within first openings formed in the first dielectric layer. A control electrode is formed over the semiconductor substrate between the first current-carrying electrode and the second current-carrying electrode. A first conductive element that includes the first conductive layer is formed over the first dielectric layer, adjacent to the control electrode, and between the control electrode and the second current-carrying electrode.

Semiconductor devices and methods of fabrication are described herein. The method includes steps for patterning fins in a multilayer stack and forming an opening in a fin and into a substrate as an initial step in forming a source/drain region. A first semiconductor material is epitaxially grown from channels exposed along sidewalls of the opening to form first source/drain structures. A second semiconductor material is epitaxially grown from the first semiconductor material to form a second source/drain structure over and to fill a space between the first source/drain structures. A bottom of the second source/drain structure is located below a bottommost surface of the first source/drain structures. The second semiconductor material has a greater concentration percentage by volume of germanium than the first semiconductor material. A stack of nanostructures is formed by removing sacrificial layers of the multilayer stack, the second semiconductor material being electrically coupled to the nanostructures.

A method for producing a transistor includes producing on a substrate provided with a semiconductor surface layer in which an active area can be formed, a gate block arranged on the active area. Lateral protection areas are formed against lateral faces of the gate block. Source and drain regions based on a metal material-semiconductor material compound are formed on either side of the gate and in the continuation of a portion located facing the gate block. Insulating spacers are formed on either side of the gate resting on the regions based on a metal material-semiconductor material compound.

A semiconductor device includes source and drain regions, a channel region between the source and drain regions, and a gate structure over the channel region. The gate structure includes a gate dielectric over the channel region, a work function metal layer over the gate dielectric and comprising iodine, and a fill metal over the work function metal layer.

A vertical semiconductor device may include a semiconductor substrate having at least one trench therein, and a superlattice layer extending vertically adjacent the at least one trench. The superlattice layer may comprise stacked groups of layers, with each group of layers comprising stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer. Each at least one non-semiconductor monolayer of each group of layers may be constrained within a crystal lattice of adjacent base semiconductor portions. The vertical semiconductor device may also include a doped semiconductor layer adjacent the superlattice layer, and a conductive body adjacent the doped semiconductor layer on a side thereof opposite the superlattice layer and defining a vertical semiconductor device contact.

A transistor device includes a first unit subcell including having a first active region width extending in a first direction, and a second unit subcell having a second active region width extending in the first direction and arranged adjacent the first unit subcell in the first direction. The first unit subcell and the second unit subcell share a common drain contact and have separate gate contacts that are aligned in the first direction. Each unit subcell includes a field plate that is connected to a source contact outside the active region and that does not cross over the gate contact.

A semiconductor device includes an enhancement mode high electron mobility transistor (HEMT) with an active region and an isolation region. The HEMT includes a substrate, a group III-V body layer, a group III-V barrier layer, a first recess, a second recess, a passivation layer, and an etch mask layer. The group III-V barrier layer includes a thinner portion, a first thicker portion and a second thicker portion in the active region, the thinner portion surrounds the first thicker portion, and the second thicker portion surrounds the thinner portion. The first recess is disposed in the group III-V barrier layer in the active region. The second recess is disposed in the group III-V barrier layer in the isolation region.