Abstract: A method for forming an epitaxial source/drain structure in a semiconductor device includes providing a substrate having a plurality of fins extending from the substrate. In some embodiments, a liner layer is formed over the plurality of fins. The liner layer is patterned to expose a first group of fins of the plurality of fins in a first region. In some embodiments, a first epitaxial layer is formed over the exposed first group of fins and a barrier layer is formed over the first epitaxial layer. Thereafter, the patterned liner layer may be removed. In various examples, a second epitaxial layer is selectively formed over a second group of fins of the plurality of fins in a second region.

Abstract: A semiconductor device structure according to the present disclosure includes a source feature and a drain feature, at least one channel structure extending between the source feature and the drain feature, a gate structure wrapped around each of the at least one channel structure, a semiconductor layer over the gate structure, a dielectric layer over the semiconductor layer, a doped semiconductor feature extending through the semiconductor layer and the dielectric layer to be in contact with the source feature, a metal contact plug over the doped semiconductor feature, and a buried power rail disposed over the metal contact plug.

Abstract: A semiconductor device includes a semiconductive substrate, a semiconductive fin, an isolation structure, a source/drain epitaxial structure, a first cap layer, and a second cap layer. The semiconductive fin protrudes from the semiconductive substrate. The isolation structure is over the semiconductive substrate and laterally surrounds the semiconductive fin. The source/drain epitaxial structure is over the semiconductive fin. The source/drain epitaxial structure has a rounded corner extending laterally and a top above the rounded corner. The first cap layer extends from the rounded corner of the source/drain epitaxial structure to the top of the source/drain epitaxial structure. The second cap layer covers the rounded corner and a bottom of the source/drain epitaxial structure. The first and second cap layers are made of different materials.

Abstract: A semiconductor device is provided. The semiconductor device includes a substrate and a semiconductor layer formed over a substrate. The semiconductor device further includes an isolation region covering the semiconductor layer and nanostructures formed over the semiconductor layer. The semiconductor layer further includes a gate stack wrapping around the nanostructures. In addition, the isolation region is interposed between the semiconductor layer and the gate stack.

Abstract: A semiconductor device includes a substrate and a semiconductor layer. The substrate includes a planar portion and a plurality of pillars on a periphery of the planar portion. The pillars are shaped as rectangular columns, and corners of two of the pillars at the same side of the planar portion are aligned in a horizontal direction or a direction perpendicular to the horizontal direction. The semiconductor layer is disposed over the planar portion and between the pillars.

Abstract: The present disclosure provides channel structures of a semiconductor device and fabricating methods thereof. The method can include forming a superlattice structure with first nanostructured layers and second nanostructured layers on a fin structure. The method can also include removing the second nanostructured layers to form multiple gate openings; forming a germanium epitaxial growth layer on the first nanostructured layers at a first temperature and a first pressure; and increasing the first temperature to a second temperature and increasing the first pressure to a second pressure over a first predetermined period of time. The method can further include annealing the germanium epitaxial growth layer at the second temperature and the second pressure in the chamber over a second predetermined period of time to form a cladding layer surrounding the first nanostructured layers.

Abstract: The present disclosure describes a semiconductor device having facet-free epitaxial structures with a substantially uniform thickness. The semiconductor device includes a fin structure on a substrate. The fin structure includes a fin bottom portion and a fin top portion. A top surface of the fin bottom portion is wider than a bottom surface of the fin top portion. The semiconductor device further includes a dielectric layer on the fin top portion, an amorphous layer on the dielectric layer, and an epitaxial layer. The epitaxial layer is on a top surface of the amorphous layer, sidewall surfaces of the amorphous layer, the dielectric layer, the fin top portion, and the top surface of the fin bottom portion.

Abstract: A strain-relaxed silicon/silicon germanium (Si/SiGe) bi-layer can be used as a foundation for constructing strained channel transistors in the form of nanosheet gate all-around field effect transistors (GAAFETs). The bi-layer can be formed using a modified silicon-on-insulator process. A superlattice can then be epitaxially grown on the bi-layer to provide either compressively strained SiGe channels for a p-type metal oxide semiconductor (PMOS) device, or tensile-strained silicon channels for an n-type metal oxide semiconductor (NMOS) device. Composition and strain of the bi-layer can influence performance of the strained channel devices.

Abstract: The present disclosure describes a method to form a semiconductor device with backside contact structures. The method includes forming a semiconductor device on a first side of a substrate. The semiconductor device includes a source/drain (S/D) region. The method further includes etching a portion of the S/D region on a second side of the substrate to form an opening and forming an epitaxial contact structure on the S/D region in the opening. The second side is opposite to the first side. The epitaxial contact structure includes a first portion in contact with the S/D region in the opening and a second portion on the first portion. A width of the second portion is larger than the first portion.

Abstract: A semiconductor device includes a substrate, a first semiconductor fin and a gate stack. The first semiconductor fin is over the substrate and includes a first germanium-containing layer and a second germanium-containing layer over the first germanium-containing layer. The first germanium-containing layer has a germanium atomic percentage higher than a germanium atomic percentage of the second germanium-containing layer. The gate stack is across the first semiconductor fin.

Abstract: A semiconductor device according to the present disclosure includes a substrate including a plurality of atomic steps that propagate along a first direction, and a transistor disposed on the substrate. The transistor includes a channel member extending a second direction perpendicular to the first direction, and a gate structure wrapping around the channel member.

Abstract: A method includes providing a p-type S/D epitaxial feature and an n-type source/drain (S/D) epitaxial feature, forming a semiconductor material layer over the n-type S/D epitaxial feature and the p-type S/D epitaxial feature, processing the semiconductor material layer with a germanium-containing gas, where the processing of the semiconductor material layer forms a germanium-containing layer over the semiconductor material layer, etching the germanium-containing layer, where the etching of the germanium-containing layer removes the germanium-containing layer formed over the n-type S/D epitaxial feature and the semiconductor material layer formed over the p-type S/D epitaxial feature, and forming a first S/D contact over the semiconductor material layer remaining over the n-type S/D epitaxial feature and a second S/D contact over the p-type S/D epitaxial feature. The semiconductor material layer may have a composition similar to that of the n-type S/D epitaxial feature.

Abstract: A method for reducing stress induced defects in heterogeneous epitaxial interfaces of a semiconductor device is disclosed. The method includes forming a fin structure with a fin base, a superlattice structure on the fin base, forming a polysilicon gate structure on the fin structure, forming a source/drain (S/D) opening within a portion of the fin structure uncovered by the polysilicon gate structure, modifying the first surfaces of the first layers to curve a profile of the first surfaces, depositing first, second, and third passivation layers on the first, second, and third surfaces, respectively, forming an epitaxial S/D region within the S/D opening, and replacing the polysilicon gate structure with a metal gate structure. The superlattice structure includes first and second layers with first and second lattice constants, respectively, and the first and second lattice constants are different from each other.

Abstract: A nano-FET and a method of forming is provided. In some embodiments, a nano-FET includes an epitaxial source/drain region contacting ends of a first nanostructure and a second nanostructure. The epitaxial source/drain region may include a first semiconductor material layer of a first semiconductor material, such that the first semiconductor material layer includes a first segment contacting the first nanostructure and a second segment contacting the second nanostructure, wherein the first segment is separated from the second segment. A second semiconductor material layer is formed over the first segment and the second segment. The second semiconductor material layer may include a second semiconductor material having a higher concentration of dopants of a first conductivity type than the first semiconductor material layer. The second semiconductor material layer may have a lower concentration percentage of silicon than the first semiconductor material layer.

Abstract: A semiconductor device structure is provided. The semiconductor device structure includes a first semiconductor nanostructure and a second semiconductor nanostructure stacked over a substrate. The semiconductor device structure also includes a first epitaxial structure connecting the first semiconductor nanostructure and a second epitaxial structure connecting the second semiconductor nanostructure. The semiconductor device structure further includes a gate stack wrapped around the first semiconductor nanostructure and the second semiconductor nanostructure. In addition, the semiconductor device structure includes a conductive contact electrically connected to the epitaxial structures. The conductive contact has a portion extending towards the gate stack from terminals of the first epitaxial structure and the second epitaxial structures. The first epitaxial structure is wider than the portion of the conductive contact.

Abstract: A device includes a semiconductive fin, an isolation structure, a gate structure, dielectric spacers, and source/drain epitaxial structures. The isolation structure surrounds a bottom portion of the semiconductive fin. The gate structure is over the semiconductive fin. The dielectric spacers are on opposite sides of the semiconductive fin and over the isolation structure. The dielectric spacers include nitride. The source/drain epitaxial structures are on opposite sides of the gate structure and over the dielectric spacers. The source/drain epitaxial structures have hexagon shapes.

Abstract: A semiconductor device is provided. The semiconductor device includes a substrate and a semiconductor layer formed over the substrate. The semiconductor device further includes a first channel layer and a second channel layer and a first insulating structure interposing the first channel layer and the semiconductor layer and a second insulating structure interposing the first channel layer and the second channel layer. The semiconductor device further includes a gate stack abutting the first channel layer and the second channel layer, and the gate stack includes a first portion vertically sandwiched between the first channel layer and the semiconductor layer and a second portion vertically sandwiched between the first channel layer and the second channel layer.

Abstract: Low-resistance contacts improve performance of integrated circuit devices that feature epitaxial source/drain regions. The low resistance contacts can be used with transistors of various types, including planar field effect transistors (FETs), FinFETs, and gate-all-around (GAA) FETs. Low-resistance junctions are formed by removing an upper portion of the source/drain region and replacing it with an epitaxially-grown boron-doped silicon germanium (SiGe) material. Material resistivity can be tuned by varying the temperature during the epitaxy process. Electrical contact is then made at the low-resistance junctions.

Abstract: A semiconductor device according to the present disclosure includes a substrate including a plurality of atomic steps that propagate along a first direction, and a transistor disposed on the substrate. The transistor includes a channel member extending a second direction perpendicular to the first direction, and a gate structure wrapping around the channel member.

Abstract: A semiconductor device includes a substrate, a first semiconductor fin and a gate stack. The first semiconductor fin is over the substrate and includes a first germanium-containing layer and a second germanium-containing layer over the first germanium-containing layer. The first germanium-containing layer has a germanium atomic percentage higher than a germanium atomic percentage of the second germanium-containing layer. The gate stack is across the first semiconductor fin.