Abstract: Semiconductor structures and methods for forming the same are provided. A semiconductor structure according to the present disclosure includes a substrate, a first base fin and a second base fin rising from the substrate, an isolation feature disposed over the substrate and between the first base fin and the second base fin, a first bottom epitaxial feature over the first base fin, a second bottom epitaxial feature over the second base fin, an isolation layer on the first bottom epitaxial feature, a first source/drain feature over the isolation layer, a second source/drain feature disposed over and in contact with the second bottom epitaxial feature, a contact etch stop layer (CESL) over the first source/drain feature and the isolation feature, a first interlayer dielectric (ILD) layer over the CESL, and a second ILD layer over and in direct contact with the second source/drain feature.

Abstract: A semiconductor device according to the present disclosure includes a dielectric fin having a helmet layer, a gate structure disposed over a first portion of the helmet layer and extending along a direction, and a dielectric layer adjacent the gate structure and disposed over a second portion of the helmet layer. A width of the first portion along the direction is greater than a width of the second portion along the direction.

Abstract: Source/drain silicide that improves performance and methods for fabricating such are disclosed herein. An exemplary device includes a first channel layer disposed over a substrate, a second channel layer disposed over the first channel layer, and a gate stack that surrounds the first channel layer and the second channel layer. A source/drain feature disposed adjacent the first channel layer, second channel layer, and gate stack. The source/drain feature is disposed over first facets of the first channel layer and second facets of the second channel layer. The first facets and the second facets have a (111) crystallographic orientation. An inner spacer disposed between the gate stack and the source/drain feature and between the first channel layer and the second channel layer. A silicide feature is disposed over the source/drain feature where the silicide feature extends into the source/drain feature towards the substrate to a depth of the first channel layer.

Abstract: The present disclosure provides a semiconductor device and a method of manufacturing the semiconductor device. The semiconductor device includes channel members vertically stacked above a substrate, a gate structure engaging the channel members, a gate sidewall spacer disposed on a sidewall of the gate structure, an epitaxial feature abutting end portions of the channel members, and inner spacers interposing the gate structure and the epitaxial feature. The end portion of at least one of the channel members includes a first dopant. A concentration of the first dopant in the end portion of the at least one of the channel members is higher than in a center portion of the at least one of the channel members. The concentration of the first dopant in the end portion of the at least one of the channel members is higher than in an outer portion of the epitaxial feature.

Abstract: A method includes forming a first fin and a second fin protruding from a frontside of a substrate, forming a gate stack over the first and second fins, forming a dielectric feature dividing the gate stack into a first segment engaging the first fin and a second segment engaging the second fin, and growing a first epitaxial feature on the first fin and a second epitaxial feature on the second fin. The dielectric feature is disposed between the first and second epitaxial features. The method also includes performing an etching process on a backside of the substrate to form a backside trench, and forming a backside via in the backside trench. The backside trench exposes the dielectric feature and the first and second epitaxial features. The backside via straddles the dielectric feature and is in electrical connection with the first and second epitaxial features.

Abstract: Methods and structures for modulating an inner spacer profile include providing a fin having an epitaxial layer stack including a plurality of semiconductor channel layers interposed by a plurality of dummy layers. In some embodiments, the method further includes removing the plurality of dummy layers to form a first gap between adjacent semiconductor channel layers of the plurality of semiconductor channel layers. Thereafter, in some examples, the method includes conformally depositing a dielectric layer to substantially fill the first gap between the adjacent semiconductor channel layers. In some cases, the method further includes etching exposed lateral surfaces of the dielectric layer to form an etched-back dielectric layer that defines substantially V-shaped recesses. In some embodiments, the method further includes forming a substantially V-shaped inner spacer within the substantially V-shaped recesses.

Abstract: The present disclosure provides a semiconductor device and a method of manufacturing the semiconductor device. The semiconductor device includes channel members disposed over a substrate, a gate structure engaging the channel members, and an epitaxial feature adjacent the channel members. At least one of the channel members has an end portion in physical contact with an outer portion of the epitaxial feature. The end portion of the at least one of the channel members includes a first dopant of a first concentration. The outer portion of the epitaxial feature includes a second dopant of a second concentration. The first concentration is higher than the second concentration.

Abstract: A method for forming a semiconductor device structure is provided. The method includes providing a substrate. The method includes forming a nanostructure stack over the substrate. The method includes forming a gate stack over the nanostructure stack and the substrate. The method includes removing the first nanostructure forming a first gap between the substrate and the second nanostructure. The method includes forming a first spacer layer in the first gap and a gate spacer over a sidewall of the gate stack. The method includes partially removing the nanostructure stack, which is not covered by the gate stack and the gate spacer, to form a first trench in the nanostructure stack. The method includes forming a source/drain structure in the first trench and over the first spacer layer.

Abstract: Source/drain silicide that improves performance and methods for fabricating such are disclosed herein. An exemplary device includes a first channel layer disposed over a substrate, a second channel layer disposed over the first channel layer, and a gate stack that surrounds the first channel layer and the second channel layer. A source/drain feature disposed adjacent the first channel layer, second channel layer, and gate stack. The source/drain feature is disposed over first facets of the first channel layer and second facets of the second channel layer. The first facets and the second facets have a (111) crystallographic orientation. An inner spacer disposed between the gate stack and the source/drain feature and between the first channel layer and the second channel layer. A silicide feature is disposed over the source/drain feature where the silicide feature extends into the source/drain feature towards the substrate to a depth of the first channel layer.

Abstract: A semiconductor device according to the present disclosure includes a dielectric fin having a helmet layer, a gate structure disposed over a first portion of the helmet layer and extending along a direction, and a dielectric layer adjacent the gate structure and disposed over a second portion of the helmet layer. A width of the first portion along the direction is greater than a width of the second portion along the direction.

Abstract: A semiconductor device according to the present disclosure includes a dielectric fin having a helmet layer, a gate structure disposed over a first portion of the helmet layer and extending along a direction, and a dielectric layer adjacent the gate structure and disposed over a second portion of the helmet layer. A width of the first portion along the direction is greater than a width of the second portion along the direction.

Abstract: A semiconductor device according to the present disclosure includes a dielectric fin having a helmet layer, a gate structure disposed over a first portion of the helmet layer and extending along a direction, and a dielectric layer adjacent the gate structure and disposed over a second portion of the helmet layer. A width of the first portion along the direction is greater than a width of the second portion along the direction.

Abstract: Source/drain silicide that improves performance and methods for fabricating such are disclosed herein. An exemplary device includes a first channel layer disposed over a substrate, a second channel layer disposed over the first channel layer, and a gate stack that surrounds the first channel layer and the second channel layer. A source/drain feature disposed adjacent the first channel layer, second channel layer, and gate stack. The source/drain feature is disposed over first facets of the first channel layer and second facets of the second channel layer. The first facets and the second facets have a (111) crystallographic orientation. An inner spacer disposed between the gate stack and the source/drain feature and between the first channel layer and the second channel layer. A silicide feature is disposed over the source/drain feature where the silicide feature extends into the source/drain feature towards the substrate to a depth of the first channel layer.

Abstract: A semiconductor device according to the present disclosure includes a dielectric fin having a helmet layer, a gate structure disposed over a first portion of the helmet layer and extending along a direction, and a dielectric layer adjacent the gate structure and disposed over a second portion of the helmet layer. A width of the first portion along the direction is greater than a width of the second portion along the direction.

Abstract: The present disclosure provides a semiconductor device and a method of manufacturing the semiconductor device. The semiconductor device includes channel members disposed over a substrate, a gate structure engaging the channel members, and an epitaxial feature adjacent the channel members. At least one of the channel members has an end portion in physical contact with an outer portion of the epitaxial feature. The end portion of the at least one of the channel members includes a first dopant of a first concentration. The outer portion of the epitaxial feature includes a second dopant of a second concentration. The first concentration is higher than the second concentration.

Abstract: A semiconductor device according to the present disclosure includes a dielectric fin having a helmet layer, a gate structure disposed over a first portion of the helmet layer and extending along a direction, and a dielectric layer adjacent the gate structure and disposed over a second portion of the helmet layer. A width of the first portion along the direction is greater than a width of the second portion along the direction.

Abstract: The present disclosure provides a method of manufacturing a semiconductor device. The method includes forming a fin structure having first semiconductor layers and second semiconductor layers alternately stacked, forming a sacrificial gate structure over the fin structure, and etching a source/drain (S/D) region thereby forming an opening exposing at least one second semiconductor layer. The method also includes implanting an etch rate modifying species into the at least one second semiconductor layer though the opening thereby forming an implanted portion of the at least one second semiconductor layer. The method further includes selectively etching the implanted portion of the at least one second semiconductor layer, recessing end portions of the first semiconductor layers exposed in the opening, and forming an S/D epitaxial layer in the opening.

Abstract: The present disclosure provides a method of manufacturing a semiconductor device. The method includes forming a fin structure having first semiconductor layers and second semiconductor layers alternately stacked, forming a sacrificial gate structure over the fin structure, and etching a source/drain (S/D) region thereby forming an opening exposing at least one second semiconductor layer. The method also includes implanting an etch rate modifying species into the at least one second semiconductor layer though the opening thereby forming an implanted portion of the at least one second semiconductor layer. The method further includes selectively etching the implanted portion of the at least one second semiconductor layer, recessing end portions of the first semiconductor layers exposed in the opening, and forming an S/D epitaxial layer in the opening.

Abstract: A method for increasing the luminous intensity of an ultraviolet light emitting diode includes heating an ultraviolet light emitting diode to a working temperature, and supplying electricity to the ultraviolet light emitting diode at the working temperature to make the ultraviolet light emitting diode emit ultraviolet light. An apparatus for increasing the luminous intensity of an ultraviolet light emitting diode includes a substrate, an ultraviolet light emitting diode mounted on the substrate, an electric heater mounted on the substrate, a temperature sensor, and a controller electrically connected to the ultraviolet light emitting diode, the electric heater, and the temperature sensor. The controller can heat the ultraviolet light emitting diode through the substrate.

Abstract: A method for increasing the luminous intensity of an ultraviolet light emitting diode includes heating an ultraviolet light emitting diode to a working temperature, and supplying electricity to the ultraviolet light emitting diode at the working temperature to make the ultraviolet light emitting diode emit ultraviolet light. An apparatus for increasing the luminous intensity of an ultraviolet light emitting diode includes a substrate, an ultraviolet light emitting diode mounted on the substrate, an electric heater mounted on the substrate, a temperature sensor, and a controller electrically connected to the ultraviolet light emitting diode, the electric heater, and the temperature sensor. The controller can heat the ultraviolet light emitting diode through the substrate.