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.

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.

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.

A semiconductor structure includes a fin extending from a substrate and oriented lengthwise in a first direction, where the fin includes a stack of semiconductor layers, an isolation feature disposed over the substrate and oriented lengthwise in a second direction perpendicular to the first direction, where the isolation feature is disposed adjacent to the fin, and a metal gate structure having a top portion disposed over the stack of semiconductor layers and a bottom portion interleaved with the stack of semiconductor layers. Furthermore, a sidewall of the bottom portion of the metal gate structure is defined by a sidewall of the isolation feature, and the top portion of the metal gate structure laterally extends over a top surface of the isolation feature.

Semiconductor structures and methods for manufacturing the same are provided. The semiconductor structure includes a substrate and first nanostructures and second nanostructures formed over the substrate. The semiconductor structure also includes a gate structure including a first portion wrapping around the first nanostructures and a second portion wrapping around the second nanostructures. The semiconductor structure also includes a dielectric feature sandwiched between the first portion and the second portion of the gate structure. In addition, the dielectric feature includes a bottom portion and a top portion over the bottom portion, and the top portion of the dielectric feature includes a shell layer and a core portion surrounded by the shell layer.

Semiconductor devices and methods of manufacturing the semiconductor devices are described herein. A method includes forming a first etch stop layer from a portion of a gate mask, the gate mask extending between spacers adjacent a gate electrode, the gate electrode overlying a semiconductor fin. The method further includes forming a second etch stop layer adjacent the first etch stop layer, forming an opening through the second etch stop layer, and exposing the first etch stop layer by performing a first etching process. The method further includes extending the opening through the first etch stop layer and exposing the gate electrode by performing a second etching process. Once the gate electrode has been exposed, the method further includes forming a gate contact in the opening.

Bi-directional trench power switches. At least one example is a semiconductor device comprising: an upper base region associated with a first side of a substrate of semiconductor material; an upper-CE trench defined on the first side, the upper-CE trench defines a proximal opening at the first side and a distal end within the substrate; an upper collector-emitter region disposed at the distal end of the upper-CE trench; a lower base region associated with a second side of substrate; and a lower collector-emitter region associated with the second side.