The present disclosure provides a method for forming a semiconductor structure. The method includes forming a layer stack on a substrate. The layer stack includes a first sub-stack, a second sub-stack on the first sub-stack and includes a plurality of sacrificial layers alternating between first and second sacrificial layers, and a third sub-stack on the second sub-stack. The method includes forming recesses in the first sacrificial layers, removing the at least one second sacrificial layer, depositing dielectric material in the at least one cavity, and depositing dielectric material in the recesses of the first sacrificial layers, wherein at least one of the acts of depositing dielectric material in the at least one cavity, and depositing dielectric material in the recesses of the first sacrificial layers, is performed by a first chemical vapor deposition method, CVD method.

A first layer is formed over a substrate; a second layer is formed over the first layer; and a third layer is formed over the second layer. The first and third layers each have a first semiconductor element; the second layer has a second semiconductor element different from the first semiconductor element. The second layer has the second semiconductor element at a first concentration in a first region and at a second concentration in a second region of the second layer. A source/drain trench is formed in a region of the stack to expose side surfaces of the layers. A first portion of the second layer is removed from the exposed side surface to form a gap between the first and the third layers. A spacer is formed in the gap. A source/drain feature is formed in the source/drain trench and on a sidewall of the spacer.

A method includes forming a transistor, which includes forming a gate dielectric on a semiconductor region, forming a gate electrode over the gate dielectric, and forming a source/drain region extending into the semiconductor region. The method further includes forming a source/drain contact plug over and electrically coupling to the source/drain region, and forming a gate contact plug over and in contact with the gate electrode. At least one of the forming the gate electrode, the forming the source/drain contact plug, and the forming the gate contact plug includes forming a metal nitride barrier layer, and depositing a metal-containing layer over and in contact with the metal nitride barrier layer. The metal-containing layer includes at least one of a cobalt layer and a metal silicide layer.

A semiconductor device includes a first fin protruding upwardly from a substrate, a second fin protruding upwardly from the substrate, a first gate structure having a first portion that at least partially wraps around an upper portion of the first fin and a second portion that at least partially wraps around an upper portion of the second fin, a second gate structure having a portion that at least partially wraps around the upper portion of the first fin, and a dielectric feature having a first portion between the first and second portions of the first gate structure. In a lengthwise direction of the first fin, the dielectric feature has a second portion extending to a sidewall of the second gate structure.

A method for manufacturing a semiconductor device includes forming a first dielectric layer over a semiconductor fin. The method includes forming a second dielectric layer over the first dielectric layer. The method includes exposing a portion of the first dielectric layer. The method includes oxidizing a surface of the second dielectric layer while limiting oxidation on the exposed portion of the first dielectric layer.

A method of fabricating a semiconductor device includes forming first gate structure and a second gate structure over a core device region of a substrate. The method further includes forming stressors at opposite sides of the first gate structure. The method further includes doping the stressors to form a first source region and a first drain region of a first device. The method further includes doping into the substrate and at opposite sides of the second gate structure to form a second source region and a second drain region of a second device, wherein the first source region, the first drain region, the second source region and the second drain region are of a same conductivity, and the first source region comprises a different material from the second source region.

The present disclosure provides a semiconductor device. The semiconductor device includes a semiconductor fin over a substrate, an epitaxial source/drain (S/D) feature disposed over the semiconductor fin, first and second dielectric layers over the substrate, and an S/D contact disposed on the epitaxial S/D feature. The first and second dielectric layers have different material compositions. A first sidewall of the epitaxial S/D feature is facing the first dielectric layer, a second sidewall of the epitaxial S/D feature is facing the second dielectric layer, and the S/D contact partially covers a top surface of the epitaxial S/D feature and extends continuously to cover the first sidewall of the epitaxial S/D feature.

A trench gate power MOSFET, including: a substrate provided with a hexagonal wide bandgap semiconductor of a first conductivity type; an epitaxial layer grown on the substrate and of the first conductivity type; a body region formed on the epitaxial layer and of a second conductivity type; a trench formed in the body region by etching, where a length direction of the trench is parallel to a projection, on the surface of a wafer, of the C axis; a second conductivity-type pillar formed by implanting first ions into a bottom region of the trench along the C axis of the hexagonal wide bandgap semiconductor material, where the bottom region of the trench is located below the trench, and is connected to the bottom of the trench, and the longitudinal depth of the second conductivity-type pillar is at least not less than 50% of the thickness of the epitaxial layer located in the bottom region of the trench; and a trench gate formed by filling the trench with a filler.

A semiconductor device includes a fin stack, a gate structure on the fin stack, a source region on a first side of the gate structure, a drain region on a second side of the gate structure opposite the first side, and a source contact extending to and connecting the source region. The source region and the drain region are asymmetric.

A method of fabricating a device includes providing a fin element in a device region and forming a dummy gate over the fin element. In some embodiments, the method further includes forming a source/drain feature within a source/drain region adjacent to the dummy gate. In some cases, the source/drain feature includes a bottom region and a top region contacting the bottom region at an interface interposing the top and bottom regions. In some embodiments, the method further includes performing a plurality of dopant implants into the source/drain feature. In some examples, the plurality of dopant implants includes implantation of a first dopant within the bottom region and implantation of a second dopant within the top region. In some embodiments, the first dopant has a first graded doping profile within the bottom region, and the second dopant has a second graded doping profile within the top region.