A method includes depositing a first work function layer over a first and second gate trench. The method includes depositing a second work function layer over the first work function layer. The method includes etching the second work function layer in the first gate trench while covering the second work function layer in the second gate trench, causing the first work function layer in the first gate trench to contain metal dopants that are left from the second work function layer etched in the first gate trench. The method includes forming a first active gate structure and second active gate structure, which include the first work function layer and the metal dopants left from the second work function layer in the first gate trench, and the first work function layer and no metal dopants left behind from the second work function layer, respectively.

A method includes etching a semiconductor substrate to form a trench between a first semiconductor strip and a second semiconductor strip. The first semiconductor strip has a first width at about 5 nm below a top of the first semiconductor strip and a second width at about 60 nm below the top of the first semiconductor strip. The first width is smaller than about 5 nm, and the second width is smaller than about 14.5 nm. The trench is filled with dielectric materials to form an isolation region, which is recessed to have a depth. A top portion of the first semiconductor strip protrudes higher than the isolation region to form a protruding fin. The protruding fin has a height smaller than the depth. A gate stack is formed to extend on a sidewall and a top surface of the protruding fin.

A method of forming a semiconductor device includes forming a first layer over a semiconductor fin and forming a second layer over the first layer. The first layer is a first material and the second layer is a second material different from the first layer. The second layer is thicker on a top of the semiconductor fin than along a sidewall of the semiconductor fin. The method further includes performing an oxidation process, the oxidation process oxidizing at least a portion of the second layer, and patterning the second layer and the first layer.

An embodiment is a method including forming a raised portion of a substrate, forming fins on the raised portion of the substrate, forming an isolation region surrounding the fins, a first portion of the isolation region being on a top surface of the raised portion of the substrate between adjacent fins, forming a gate structure over the fins, and forming source/drain regions on opposing sides of the gate structure, wherein forming the source/drain regions includes epitaxially growing a first epitaxial layer on the fin adjacent the gate structure, etching back the first epitaxial layer, epitaxially growing a second epitaxial layer on the etched first epitaxial layer, and etching back the second epitaxial layer, the etched second epitaxial layer having a non-faceted top surface, the etched first epitaxial layer and the etched second epitaxial layer forming source/drain regions.

An integrated circuit device includes: a fin-type active area protruding from a substrate, extending in a first direction parallel to an upper surface of the substrate, and including a first semiconductor material; an isolation layer arranged on the substrate and covering a lower portion of a sidewall of the fin-type active area, the isolation layer including an insulation liner conformally arranged on the lower portion of the sidewall of the fin-type active area, and an insulation filling layer on the insulation liner; a capping layer surrounding an upper surface and the sidewall of the fin-type active area, including a second semiconductor material different from the first semiconductor material, and with the capping layer having an upper surface, a sidewall, and a facet surface between the upper surface and the sidewall; and a gate structure arranged on the capping layer and extending in a second direction perpendicular to the first direction.

A method for manufacturing a semiconductor structure includes etching trenches in a semiconductor substrate to form a semiconductor fin between the trenches; converting sidewalls of the semiconductor fin into hydrogen-terminated surfaces each having silicon-to-hydrogen (S—H) bonds; after converting the sidewalls of the semiconductor fin into the hydrogen-terminated surfaces, depositing a dielectric material overfilling the trenches; and etching back the dielectric material to fall below a top surface of the semiconductor fin.

Methods and semiconductor devices are provided. A vertical junction field effect transistor (JFET) includes a substrate, an active region having a plurality of semiconductor fins, a source metal layer on an upper surface of the fins, a source metal pad layer coupled to the semiconductor fins through the source metal layer, a gate region surrounding the semiconductor fins, and a body diode surrounding the gate region.

A method of fabricating a semiconductor device includes forming a gate structure, a first edge structure and a second edge structure on a semiconductor strip. The method further includes forming a first source/drain feature between the gate structure and the first edge structure. The method further includes forming a second source/drain feature between the gate structure and the second edge structure, wherein a distance between the gate structure and the first source/drain feature is different from a distance between the gate structure and the second source/drain feature. The method further includes implanting a buried channel in the semiconductor strip, wherein the buried channel is entirely below a top-most surface of the semiconductor strip, a maximum depth of the buried channel is less than a maximum depth of the first source/drain feature, and a dopant concentration of the buried channel is highest under the gate structure.

A method of forming a power rail to semiconductor devices comprising removing a portion of the gate structure forming a gate cut trench separating a first active region of fin structures from a second active region of fin structures. A conformal etch stop layer is formed in the gate cut trench. A fill material is formed on the conformal etch stop layer filling at least a portion of the gate cut trench. The fill material has a composition that is etched selectively to the conformal etch stop layer. A power rail is formed in the gate cut trench. The conformal etch stop layer obstructs lateral etching during forming the power rail to substantially eliminate power rail to gate structure shorting.

A semiconductor device includes a first semiconductor layer below a second semiconductor layer; first and second gate dielectric layers surrounding the first and the second semiconductor layers, respectively; and a gate electrode surrounding both the first and the second gate dielectric layers. The first gate dielectric layer has a first top section above the first semiconductor layer and a first bottom section below the first semiconductor layer. The second gate dielectric layer has a second top section above the second semiconductor layer and a second bottom section below the second semiconductor layer. The first top section has a first thickness. The second top section has a second thickness. The second thickness is greater than the first thickness.