Abstract: Semiconductor structures and method for forming the same are provided. The semiconductor structure includes channel structures vertically separated from each other and a gate structure wrapping around the channel structures. The semiconductor structure further includes a first porous layer formed over a first sidewall of the gate structure under the channel structures and a source/drain structure attached to the channel structures. In addition, the source/drain structure is laterally separated from the first porous layer by a first air gap.

Abstract: A method includes following steps. A semiconductor fin is formed on a substrate. A source/drain recess is formed in the semiconductor fin. A first isolation sidewall dielectric and a second isolation sidewall dielectric are formed lining opposite sidewalls of the source/drain recess. An epitaxial layer is formed in the source/drain recess. The epitaxial layer is recessed such that a top surface of the epitaxial layer is lower than top surfaces of the first and second isolation sidewall dielectrics. An epitaxial source/drain region is formed on the recessed epitaxial layer. A gate structure is formed adjacent the epitaxial source/drain region.

Abstract: A method for forming a semiconductor structure is provided. The method includes forming a first fin structure in a first p-type device region and a second fin structure in a second p-type device region. Each of the first fin structure and the second fin structure includes alternatingly stacking first semiconductor layers and second semiconductor layers. The method also includes etching the first fin structure and the second fin structure to form a first recess and a second recess, respectively, forming a first patterned mask layer to cover the second p-type device region, laterally recessing the second semiconductor layers of the first fin structure to form first notches, removing the first patterned mask layer, forming a first p-type source/drain feature in the first recess and the notches, and forming a second p-type source/drain feature in the second recess.

Abstract: Self-aligned gate cutting techniques are disclosed herein that provide dielectric gate isolation fins for isolating gates of multigate devices from one another. An exemplary device includes a first multigate device having first source/drain features and a first metal gate that surrounds a first channel layer and a second multigate device having second source/drain features and a second metal gate that surrounds a second channel layer. A dielectric gate isolation fin separates the first metal gate from the second metal gate. The dielectric gate isolation fin includes a first dielectric layer having a first dielectric constant and a second dielectric layer having a second dielectric constant disposed over the first dielectric layer. The second dielectric constant is greater than the first dielectric constant. The first metal gate and the second metal gate physically contact the first channel layer and the second channel layer, respectively, and the dielectric gate isolation fin.

Abstract: A method for forming a gate all around transistor includes forming a plurality of semiconductor nanosheets. The method includes forming a cladding inner spacer between a source region of the transistor and a gate region of the transistor. The method includes forming sheet inner spacers between the semiconductor nanosheets in a separate deposition process from the cladding inner spacer.

Abstract: The present disclosure provides a method of forming N-type and P-type source/drain features using one patterned mask and one self-aligned mask to increase windows of error tolerance and provide flexibilities for source/drain features of various shapes and/or volumes. The present disclosure also includes forming a trench between neighboring source/drain features to remove bridging between the neighboring source/drain features. In some embodiments, the trenches between the source/drain features are formed by etching from the backside of the substrate.

Abstract: A semiconductor structure includes a plurality of nanosheets, a gate structure, an S/D structure, a stepped structure, and a sidewall spacer. The plurality of nanosheets is disposed over a substrate, wherein the substrate extends along a first direction, and the nanosheets are arranged along a second direction substantially perpendicular to the first direction. The gate structure is disposed over the substrate, wherein the gate structure is disposed between and surrounding the nanosheets. The S/D structure is disposed adjacent to the gate structure and the plurality of nanosheets. The stepped structure is disposed below the S/D structure, wherein the stepped structure overlaps at least one of the nanosheets along the first direction. The sidewall spacer is disposed between the stepped structure and the at least one of the nanosheets. A method of manufacturing the semiconductor structure is also provided.

Abstract: Semiconductor devices using a dielectric structure and methods of manufacturing are described herein. The semiconductor devices are directed towards gate-all-around (GAA) devices that are formed over a substrate and are isolated from one another by the dielectric structure. The dielectric structure is formed over the fin between two GAA devices and cuts a gate electrode that is formed over the fin into two separate gate electrodes. The two GAA devices are also formed with bottom spacers underlying source/drain regions of the GAA devices. The bottom spacers isolate the source/drain regions from the substrate. The dielectric structure is formed with a shallow bottom that is located above the bottoms of the bottom spacers.

Abstract: Corner portions of a semiconductor fin are kept on the device while removing a semiconductor fin prior to forming a backside contact. The corner portions of the semiconductor fin protect source/drain regions from etchant during backside processing. The corner portions allow the source/drain features to be formed with a convex profile on the backside. The convex profile increases volume of the source/drain features, thus, improving device performance. The convex profile also increases processing window of backside contact recess formation.

Abstract: Semiconductor structures and methods for manufacturing the same are provided. The semiconductor structure includes nanostructures formed over a substrate along a first direction, and a gate structure formed over the nanostructures along a second direction. The semiconductor structure includes an S/D structure formed adjacent to the gate structure, and a plurality of inner spacer layers between the gate structure and the S/D structure. The semiconductor structure includes a hard mask layer formed on the inner spacer layers, and a top surface of the hard mask layer is higher than a top surface of the S/D structure.

Abstract: An integrated circuit includes a first nanostructure transistor including a plurality of first semiconductor nanostructures over a substrate and a source/drain region in contact with each of the first semiconductor nanostructures. The integrated circuit includes a second nanostructure transistor including a plurality of second semiconductor nanostructures and a second source/drain region in contact with one or more of the second semiconductor nanostructures but not in contact with one or more other second semiconductor nanostructures.

Abstract: A semiconductor device structure, along with methods of forming such, are described. The structure includes a stack of semiconductor layers spaced apart from and aligned with each other, a first source/drain epitaxial feature in contact with a first one or more semiconductor layers of the stack of semiconductor layers, and a second source/drain epitaxial feature disposed over the first source/drain epitaxial feature. The second source/drain epitaxial feature is in contact with a second one or more semiconductor layers of the stack of semiconductor layers. The structure further includes a first dielectric material disposed between the first source/drain epitaxial feature and the second source/drain epitaxial feature and a first liner disposed between the first source/drain epitaxial feature and the second source/drain epitaxial feature. The first liner is in contact with the first source/drain epitaxial feature and the first dielectric material.

Abstract: A semiconductor device structure is provided. The semiconductor device structure includes a plurality of first nanostructures stacked over a substrate in a vertical direction. The semiconductor device structure also includes a first bottom layer formed adjacent to the first nanostructures, and a first dielectric liner layer formed over the first bottom layer and adjacent to the first nanostructures. The semiconductor device structure further includes a first source/drain (S/D) structure formed over the first dielectric liner layer, and the first S/D structure is isolated from the first bottom layer by the first dielectric liner layer.

Abstract: An integrated circuit includes a first nanostructure transistor and a second nanostructure transistor on a substrate. The source/drain regions of the first nanostructure are electrically isolated from the semiconductor substrate by dielectric barriers. The source/drain regions of the second nanostructure transistor in direct contact with the semiconductor substrate.

Abstract: Semiconductor structures and methods for manufacturing the same are provided. The semiconductor structure includes a substrate and a bottom isolation feature formed over the substrate. The semiconductor structure also includes a bottom semiconductor layer formed over the bottom isolation feature and nanostructures formed over the bottom semiconductor layer. The semiconductor structure also includes a source/drain structure attached to the nanostructures and covering a portion of the bottom isolation feature.

Abstract: A method for forming a gate all around transistor includes forming a plurality of semiconductor nanosheets. The method includes forming a cladding inner spacer between a source region of the transistor and a gate region of the transistor. The method includes forming sheet inner spacers between the semiconductor nanosheets in a separate deposition process from the cladding inner spacer.

Abstract: A semiconductor device includes two source/drain regions, two isolation elements, a channel feature, at least one semiconductor layer and a gate feature. The source/drain regions are spaced apart from each other, and are respectively disposed above the isolation elements. The channel feature includes at least one effective channel layer and at least one dummy channel layer that are spaced apart from each other. Each of the at least one effective channel layer extends between the source/drain regions. Each of the at least one dummy channel layer extends between the isolation elements. The at least one semiconductor layer at least covers a lower surface of a bottommost one of the at least one dummy channel layer. The gate feature is disposed around the at least one effective channel layer, such that two opposite surfaces of each of the at least one effective channel layer are adjacent to the gate feature.

Abstract: A semiconductor device includes a substrate, an active structure, a first dielectric layer and a second dielectric layer. The active structure is formed on the substrate and includes an active channel sheet, wherein the active channel sheet has a first lateral surface. The first dielectric layer is formed above the active structure and has a recess, wherein the recess is recessed with respect to the first lateral surface of the active channel sheet. The second dielectric layer is formed within the recess and has a dielectric constant, wherein the dielectric constant is less than 3.9.

Abstract: A device includes a substrate. A first channel region of a first transistor overlies the substrate and a source/drain region is in contact with the first channel region. The source/drain region is adjacent to the first channel region along a first direction, and the source/drain region has a first surface opposite the substrate and side surfaces extending from the first surface. A dielectric fin structure is adjacent to the source/drain region along a second direction that is transverse to the first direction, and the dielectric fin structure has an upper surface, a lower surface, and an intermediate surface that is disposed between the upper and lower surfaces. A silicide layer is disposed on the first surface and the side surfaces of the source/drain region and on the intermediate surface of the dielectric fin structure.

Abstract: The present disclosure provides a method of forming N-type and P-type source/drain features using one patterned mask and one self-aligned mask to increase windows of error tolerance and provide flexibilities for source/drain features of various shapes and/or volumes. The present disclosure also includes forming a trench between neighboring source/drain features to remove bridging between the neighboring source/drain features. In some embodiments, the trenches between the source/drain features are formed by etching from the backside of the substrate.