A method includes forming a semiconductive channel layer on a substrate. A dummy gate is formed on the semiconductive channel layer. Gate spacers are formed on opposite sides of the dummy gate. The dummy gate is removed to form a gate trench between the gate spacers, resulting in the semiconductive channel layer exposed in the gate trench. A semiconductive protection layer is deposited in the gate trench and on the exposed semiconductive channel layer. A top portion of the semiconductive protection layer is oxidized to form an oxidation layer over a remaining portion of the semiconductive protection layer. The oxidation layer is annealed after the top portion of the semiconductive protection layer is oxidized. A gate structure is formed over the semiconductive protection layer and in the gate trench after the oxidation layer is annealed.

A semiconductor device with isolation structures and a method of fabricating the same are disclosed. The method includes forming a fin structure on a substrate forming a superlattice structure with first and second nanostructured layers on the fin structure, forming a source/drain (S/D) opening in the superlattice structure, forming an isolation opening in the fin structure and below the S/D opening, forming a first isolation layer in the isolation opening, selectively forming an oxide layer on sidewalls of the S/D opening, selectively forming an inhibitor layer on the oxide layer, selectively depositing a second isolation layer on the first isolation layer, and forming S/D regions in the S/D opening on the second isolation layer.

A semiconductor device includes a first active region, a second active region spaced apart from the first active region, a plurality of first channel layers disposed on the first active region, and a second channel layer disposed on the second active region. The semiconductor device further includes a first gate structure intersecting the first active region and the first channel layers, a second gate structure intersecting the second active region and the second channel layer, a first source/drain region disposed on the first active region and contacting the plurality of first channel layers, and a second source/drain region and contacting the second channel layer. The plurality of first channel layers includes a first uppermost channel layer and first lower channel layers disposed below the first uppermost channel layer, and the first uppermost channel layer includes a material that is different from a material included in the first lower channel layers.

The present disclosure describes a semiconductor device and methods for forming the same. The semiconductor device includes nanostructures on a substrate and a source/drain region in contact with the nanostructures. The source/drain region includes epitaxial end caps, where each epitaxial end cap is formed at an end portion of a nanostructure of the nanostructures. The source/drain region also includes an epitaxial body in contact with the epitaxial end caps and an epitaxial top cap formed on the epitaxial body. The semiconductor device further includes gate structure formed on the nanostructures.

A varactor transistor includes a semiconductor fin having a first conductivity type, a plurality of gate structures separated from each other and surrounding a portion of the semiconductor fin. The plurality of gates structures include a dummy gate structure on an edge of the semiconductor fin, and a first gate structure spaced apart from the dummy gate structure. The dummy gate structure and the gate structure each include a gate insulator layer on a surface portion of the semiconductor fin, a gate on the gate insulator layer, and a spacer on the gate. The varactor transistor also includes a raised source/drain region on the semiconductor fin and between the dummy gate structure and the first gate structure, the raised source/drain region and the gate of the dummy gate structure being electrically connected to a same potential.

A semiconductor device includes an active region extending on a substrate in a first direction and including an impurity region, a plurality of channel layers vertically spaced apart from each other on the active region, a gate structure extending on the substrate in a second direction to intersect the active region and the plurality of channel layers, and surrounding the plurality of channel layers, a source/drain region disposed on the active region on at least one side of the gate structure and in contact with the plurality of channel layers, a barrier layer including a first barrier layer spaced apart from an upper surface of the active region and being disposed in the active region, and second barrier layers respectively disposed below the plurality of channel layers, and a contact plug connected to the source/drain region.

A semiconductor device including an insulating layer on a substrate; channel semiconductor patterns stacked on the insulating layer and vertically spaced apart from each other; a gate electrode crossing the channel semiconductor patterns; source/drain regions respectively at both sides of the gate electrode and connected to each other through the channel semiconductor patterns, the source/drain regions having concave bottom surfaces; and air gaps between the insulating layer and the bottom surfaces of the source/drain regions.

A semiconductor device according to the present disclosure includes a channel portion, a gate electrode disposed opposite the channel portion via a gate insulating film, and source/drain regions disposed at both edges of the channel portion. The source/drain regions include semiconductor layers that have a first conductivity type and that are formed inside recessed portions disposed on a base body. Impurity layers having a second conductivity type different from the first conductivity type are formed between the base body and bottom portions of the semiconductor layers.

A mist-CVD apparatus contains a first atomizer for atomizing a first metal oxide precursor and generating a first mist of the first metal oxide precursor; a second atomizer for atomizing a second metal oxide precursor and generating a second mist of the second metal oxide precursor; a carrier-gas supplier for supplying a carrier gas to convey the first and second mists; a film-forming unit for forming a film on a substrate by subjecting the first and second mists to a thermal reaction; and a first conveyance pipe through which the first mist and the carrier gas are conveyed to the film forming chamber, a second conveyance pipe through which the second mist and the carrier gas are conveyed to the film forming chamber.

A semiconductor device and a method of forming the same are provided. In an embodiment, an exemplary semiconductor device includes two stacks of channel members; a source/drain feature extending between the two stacks of channel members along a direction; a source/drain contact disposed under and electrically coupled to the source/drain feature; two gate structures over and interleaved with the two stacks of channel members; a low-k spacer horizontally surrounding the source/drain contact; and a dielectric layer horizontally surrounding the low-k spacer.