Abstract: A method includes forming a stack of channel layers and sacrificial layers on a substrate. The channel layers and the sacrificial layers have different material compositions and being alternatingly disposed in a vertical direction. The method further includes patterning the stack to form a semiconductor fin, forming an isolation feature on sidewalls of the semiconductor fin, recessing the semiconductor fin, thereby forming a source/drain recess, such that a recessed top surface of the semiconductor fin is below a top surface of the isolation feature, growing a base epitaxial layer from the recessed top surface of the semiconductor fin, depositing an insulation layer in the source/drain recess, and forming an epitaxial feature in the source/drain recess, wherein the epitaxial feature is above the insulation layer. The insulation layer is above the base epitaxial layer and above a bottommost channel layer.

Abstract: The present disclosure provides a method of making a semiconductor device. The method includes forming a semiconductor stack on a substrate, wherein the semiconductor stack includes first semiconductor layers of a first semiconductor material and second semiconductor layers of a second semiconductor material alternatively stacked on the substrate; patterning the semiconductor stack and the substrate to form a trench and an active region being adjacent the trench; epitaxially growing a liner of the first semiconductor material on sidewalls of the trench and sidewalls of the active region; forming an isolation feature in the trench; performing a rapid thermal nitridation process, thereby converting the liner into a silicon nitride layer; and forming a cladding layer of the second semiconductor material over the silicon nitride layer.

Abstract: A semiconductor structure includes a semiconductor substrate; fin active regions protruded above the semiconductor substrate; and a gate stack disposed on the fin active regions; wherein the gate stack includes a high-k dielectric material layer, and various metal layers disposed on the high-k dielectric material layer. The gate stack has an uneven profile in a sectional view with a first dimension D1 at a top surface, a second dimension D2 at a bottom surface, and a third dimension D3 at a location between the top surface and the bottom surface, and wherein each of D1 and D2 is greater than D3.

Abstract: Semiconductor structures and methods of forming the same are provided. A method according to the present disclosure includes forming a stack of epitaxial layers over a substrate, forming a first fin-like structure and a second fin-like structure from the stack, forming an isolation feature between the first fin-like structure and the second fin-like structure, forming a cladding layer over the first fin-like structure and the second fin-like structure, conformally depositing a first dielectric layer over the cladding layer, depositing a second dielectric layer over the first dielectric layer, planarizing the first dielectric layer and the second dielectric layer until the cladding layer are exposed, performing an etch process to etch the second dielectric layer to form a helmet recess, performing a trimming process to trim the first dielectric layer to widen the helmet recess, and depositing a helmet feature in the widened helmet recess.

Abstract: A method includes forming a semiconductor substrate, forming hard mask layers (HMs) over the semiconductor substrate, forming first mandrels over the HMs, forming second mandrels along sidewalls of the first mandrels, forming a protective layer over the first mandrels and the second mandrels, removing a portion of the protective layer to expose portions of the first and the second mandrels, removing the exposed portions of the second mandrels with respect to the exposed portions of the first mandrels, removing remaining portions of the protective layer to expose remaining portions of the first and second mandrels, where the exposed portions of the first mandrels and the remaining portions of the first and second mandrels form a mandrel structure, patterning the HMs using the mandrel structure as an etching mask, and patterning the semiconductor substrate to form a fin structure using the patterned HMs as an etching mask.

Abstract: A semiconductor device includes a plurality of nanostructures extending in a first direction above a semiconductor substrate and arranged in a second direction substantially perpendicular to the first direction and a gate structure extending in a third direction perpendicular to both the first and second directions, the gate structure surrounding each of the plurality of nano structures. Each of the plurality of nanostructures has an outer region having a composition different from a composition of an inner region of each of the plurality of the nanostructures. The gate structure includes a plurality of high-k gate dielectric layers respectively surrounding the plurality of nanostructures, a work function layer surrounding each of the plurality of high-k gate dielectric layers and a fill metal layer surrounding the work function layer.

Abstract: A semiconductor structure includes fins protruding from a substrate and separated by a dielectric layer, each semiconductor fin including a plurality of semiconductor layers, source/drain (S/D) features disposed in the semiconductor fins, a first metal gate stack and a second metal gate stack disposed over the semiconductor fins and adjacent to the S/D features, where the first and the second metal gate stacks each include a top portion and a bottom portion disposed below the top portion, and where the bottom portion is interleaved with the semiconductor layers, and an isolation feature disposed on the dielectric layer and in contact with a sidewall surface of each of the first and the second metal gate stacks, where the isolation feature protrudes from the top portion of the first and the second metal gate stack, and where the isolation feature includes two compositionally different dielectric layers.

Abstract: A plurality of first semiconductor layers and second semiconductor layers are formed over a front side of a substrate. The first semiconductor layers interleave with the second semiconductor layers in a vertical direction. The first semiconductor layers and second semiconductor layers are etched into a plurality of stacks. The etching is performed such that a bottommost first semiconductor layer is etched to have a tapered profile in a cross-sectional view. The bottommost first semiconductor layer is replaced with a dielectric layer. The dielectric layer inherits the tapered profile of the bottommost first semiconductor layer. Gate structures are formed over the stacks. The gate structures each extend in a first horizontal direction. A first interconnect structure is formed over the gate structures. A second interconnect structure is formed over a back side of the substrate.

Abstract: A semiconductor device includes a source/drain feature over a semiconductor substrate, channel layers connected to the source/drain feature, a gate structure between adjacent channel layers and wrapping the channel layers, and an inner spacer between the source/drain feature and the gate structure and between adjacent channel layers. The source/drain feature has a first interface with a first channel layer of the channel layer. The first interface has a convex profile protruding towards the first channel layer.

Abstract: A semiconductor structure that includes a first semiconductor fin and a second semiconductor fin disposed over a substrate and adjacent to each other, a metal gate stack disposed over the substrate, and source/drain features disposed in each of the first semiconductor fin and the second semiconductor fin to engage with the metal gate stack. The metal gate stack includes a first region disposed over the first semiconductor fin, a second region disposed over the second semiconductor fin, and a third region connecting the first region to the second region in a continuous profile, where the first region is defined by a first gate length and the second region is defined by a second gate length less than the first gate length.

Abstract: 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.

Abstract: A semiconductor device includes a pair of fin structures on a semiconductor substrate, each including a vertically stacked plurality of channel layers, a dielectric fin extending in parallel to and between the fin structures, and a gate structure on and extending perpendicularly to the fin structures, the gate structure engaging with the plurality of channel layers. The dielectric fin includes a fin bottom and a fin top over the fin bottom. The fin bottom has a top surface extending above a bottom surface of a topmost channel layer. The fin top includes a core and a shell, the core having a first dielectric material, the shell surrounding the core and having a second dielectric material different from the first dielectric material.

Abstract: In a method of manufacturing a semiconductor device, a fin structure, which includes a stacked layer of first semiconductor layers and second semiconductor layers disposed over a bottom fin structure and a hard mask layer over the stacked layer, is formed. An isolation insulating layer is formed. A sacrificial cladding layer is formed over at least sidewalls of the exposed hard mask layer and stacked layer. A first dielectric layer is formed. A second dielectric layer is formed over the first dielectric layer. The second dielectric layer is recessed. A third dielectric layer is formed on the recessed second dielectric layer. The third dielectric layer is partially removed to form a trench. A fourth dielectric layer is formed by filling the trench with a dielectric material, thereby forming a wall fin structure.

Abstract: A method includes providing a semiconductor substrate having a first region and a second region, epitaxially growing a semiconductor layer above the semiconductor substrate, patterning the semiconductor layer to form a first fin in the first region and a second fin in the second region, and depositing a dielectric material layer on sidewalls of the first and second fins. The method also includes performing an anneal process in driving dopants into the dielectric material layer, such that a dopant concentration in the dielectric material layer in the first region is higher than that in the second region, and performing an etching process to recess the dielectric material layer, thereby exposing the sidewalls of the first and second fins. A top surface of the recessed dielectric material layer in the first region is lower than that in the second region.

Abstract: A method includes forming a p-well and an n-well in a substrate. The method further includes forming a stack of interleaving first semiconductor layers and second semiconductor layers over the p-well and the n-well, the first semiconductor layers having a first thickness and the second semiconductor layers having a second thickness different than the first thickness. The method further includes annealing the stack of interleaving semiconductor layers. The method further includes patterning the stack to form fin-shaped structures including a first fin-shaped structure over the n-well and a second fin-shaped structure over the p-well. The method further includes etching to remove the second semiconductor layers from the first and second fin-shaped structures, where the first semiconductor layers have a different thickness within each of the first and second fin-shaped structures after the etching. The method further includes forming a metal gate over the first and second fin-shaped structures.

Abstract: Semiconductor structures and methods of forming the same are provided. A method according to the present disclosure includes forming a stack of epitaxial layers over a substrate, forming a first fin-like structure and a second fin-like structure from the stack, forming an isolation feature between the first fin-like structure and the second fin-like structure, forming a cladding layer over the first fin-like structure and the second fin-like structure, conformally depositing a first dielectric layer over the cladding layer, depositing a second dielectric layer over the first dielectric layer, planarizing the first dielectric layer and the second dielectric layer until the cladding layer are exposed, performing an etch process to etch the second dielectric layer to form a helmet recess, performing a trimming process to trim the first dielectric layer to widen the helmet recess, and depositing a helmet feature in the widened helmet recess.

Abstract: Semiconductor structures and methods of forming the same are provided. A method according to the present disclosure includes forming a stack of epitaxial layers over a substrate, forming a first fin-like structure and a second fin-like structure from the stack, forming an isolation feature between the first fin-like structure and the second fin-like structure, forming a cladding layer over the first fin-like structure and the second fin-like structure, conformally depositing a first dielectric layer over the cladding layer, depositing a second dielectric layer over the first dielectric layer, planarizing the first dielectric layer and the second dielectric layer until the cladding layer are exposed, performing an etch process to etch the second dielectric layer to form a helmet recess, performing a trimming process to trim the first dielectric layer to widen the helmet recess, and depositing a helmet feature in the widened helmet recess.

Abstract: A method for manufacturing a semiconductor structure includes forming a fin over a substrate, wherein the fin includes first semiconductor layers and second semiconductor layers alternating stacked. The method also includes forming an isolation feature around the fin, forming a dielectric feature over the isolation feature, forming a cap layer over the fin and the dielectric feature, oxidizing the cap layer to form an oxidized cap layer, forming source/drain features passing through the cap layer and in the fin, removing the second semiconductor layers in the fin to form nanostructures, and forming a gate structure wrapping around the nanostructures.

Abstract: The present disclosure provides methods of forming semiconductor devices. A method according to the present disclosure includes receiving a workpiece that includes a stack of semiconductor layers, depositing a first pad oxide layer on a germanium-containing top layer of the stack, depositing a second pad oxide layer on the first pad oxide layer, depositing a pad nitride layer on the second pad oxide layer, and patterning the stack using the first pad oxide layer, the second pad oxide layer, and the pad nitride layer as a hard mask layer. The depositing of the first pad oxide layer includes a first oxygen plasma power and the depositing of the second pad oxide layer includes a second oxygen plasma power greater than the first oxygen plasma power.

Abstract: An integrated circuit (IC) structure includes a gate structure, a source epitaxial structure, a drain epitaxial structure, a front-side interconnection structure, a backside dielectric layer, and a backside via. The source epitaxial structure and the drain epitaxial structure are respectively on opposite sides of the gate structure. The front-side interconnection structure is on a front-side of the source epitaxial structure and a front-side of the drain epitaxial structure. The backside dielectric layer is on a backside of the source epitaxial structure and a backside of the drain epitaxial structure and has an air gap therein. The backside via extends through the backside dielectric layer to a first one of the source epitaxial structure and the drain epitaxial structure.