A multi-stack semiconductor device includes: a lower-stack transistor structure including a lower active region and a lower gate structure, the lower active region including a lower channel structure, and the lower gate structure surrounding the lower channel structure; an upper-stack transistor structure vertically stacked above the lower-stack transistor structure, and including an upper active region and an upper gate structure, the upper active region including an upper channel structure, and the upper gate structure surrounding the upper channel structure; and at least one gate contact plug contacting a top surface of the lower gate structure, wherein the lower gate structure and the upper gate structure have a substantially same size in a plan view, and wherein the lower gate structure is not entirely overlapped by the upper gate structure in a vertical direction.

A semiconductor device includes at least one active region, a first dielectric layer, a gate structure, and an air void. The active region includes a III-V compound semiconductor layer. The first dielectric layer is disposed on the active region. The gate structure is disposed on the active region, and at least a part of the gate structure is disposed in the first dielectric layer. The air void is disposed in the first dielectric layer, and at least a part of the air void is disposed at two opposite sides of the gate structure in a horizontal direction.

In an entire intermediate region between an active region and an edge termination region, a p.sup.+-type region is provided between a p-type base region and a parallel pn layer. The p.sup.+-type region is formed concurrently with and in contact with p.sup.+-type regions for mitigating electric field near bottoms of gate trenches. The p.sup.+-type region has portions that face, respectively, n-type regions and p-type regions of a parallel pn layer in a depth direction Z and at the portions, has protrusions that protrude toward the parallel pn layer. N-type current spreading regions extend in the entire intermediate region from the active region and are between the p.sup.+-type region and the parallel pn layer, positioned between protrusions of the p.sup.+-type region. The impurity concentration of the n-type current spreading regions in the gate region is higher than that of those in other regions. Thus, avalanche capability may be enhanced.

A transistor device and a method for forming a transistor device are disclosed. The transistor device includes: a SiC semiconductor body that includes a first semiconductor layer and a second semiconductor layer formed on top of the first semiconductor; a trench structure extending from a first surface of the semiconductor body through the second semiconductor layer into the first semiconductor layer; a drain region arranged in the first semiconductor layer; and a plurality of transistor cells each coupled between the drain region and a source node. The trench structure subdivides the second semiconductor layer into a plurality of mesa regions and includes at least one cavity. At least one of the plurality of transistor cells is at least partially integrated in each of the mesa regions.

Techniques are provided to form semiconductor devices having a multi-layer spacer structure. In an example, a semiconductor device includes a semiconductor region extending between a source region and a drain region, and a gate layer extending over the semiconductor region. A spacer structure made up of one or more dielectric layers is present along a sidewall of the gate structure and along a sidewall of the source region or the drain region. The spacer structure has three different portions: a first portion along the sidewall of the gate, a second portion along the sidewall of the source or drain region, and a third portion that connects between the first two portions. The third portion of the spacer structure has a multi-layer configuration while the first and second portions have a fewer number of material layers.

An integrated circuit (IC) device includes a chip having a semiconductor substrate and a thermoelectric module embedded in the semiconductor substrate, where the thermoelectric module includes a first semiconductor structure electrically connected to a second semiconductor structure, where a bottom portion of thermoelectric module extends through a thickness of the semiconductor substrate, and where the first semiconductor structure and the second semiconductor structure include dopants of different conductivity types.

A semiconductor device includes a first gate structure and a second gate structure over a fin, a dielectric cut pattern sandwiched by the first and second gate structures, and a liner layer surrounding the dielectric cut pattern. The dielectric cut pattern is spaced apart from the fin and extends further from the substrate than a first gate electrode of the first gate structure and a second gate electrode of the second gate structure. The semiconductor device further includes a conductive feature sandwiched by the first and second gate structures. The conductive feature is divided by the conductive feature into a first segment and a second segment. The first segment of the conductive feature is above a source/drain region of the fin.

A method of producing a power semiconductor device includes: providing a semiconductor body; forming, at the semiconductor body, a polycrystalline semiconductor region; forming, at the polycrystalline semiconductor region, an amorphous sublayer; subjecting the amorphous sublayer to a re-crystallization processing step to form a re-crystallized sublayer; and forming a metal layer at the re-crystallized sublayer.

Semiconductor structures and methods are provided. An exemplary method according to the present disclosure includes receiving a fin-shaped structure comprising a first channel region and a second channel region, a first and a second dummy gate structures disposed over the first and the second channel regions, respectively. The method also includes removing a portion of the first dummy gate structure, a portion of the first channel region and a portion of the substrate under the first dummy gate structure to form a trench, forming a hybrid dielectric feature in the trench, removing a portion of the hybrid dielectric feature to form an air gap, sealing the air gap, and replacing the second dummy gate structure with a gate stack after sealing the air gap.

A method of forming a semiconductor device is provided. The method includes providing a substrate having a first region and a second region; forming a plurality of trenches in the first region of the substrate; forming a multi-layer stack over the substrate and in the trenches; and patterning the multi-layer stack and the substrate to form first nanostructures over first fins in the first region and second nanostructures over second fins in the second region, where the multi-layer stack includes at least one of first semiconductor layers and at least one of second semiconductor layer stacked alternately, and the plurality of trenches are in corresponding ones of the first fins.