Abstract: Semiconductor structures and the manufacturing method thereof are disclosed. An exemplary semiconductor structure according to the present disclosure includes a substrate having a p-type well or an n-type well, a first base portion over the p-type well, a second base portion over the n-type well, a first plurality of channel members over the first base portion, a second plurality of channel members over the second base portion, an isolation feature disposed between the first base portion and the second base portion, and a deep isolation structure in the substrate disposed below the isolation feature.

Abstract: A semiconductor device structure is provided. The structure includes a first gate electrode layer having at least three surfaces surrounded by a first intermixed layer, wherein the first intermixed layer comprises a first material and a second material. The structure also includes a second gate electrode layer disposed below and in contact with the first gate electrode layer, the second gate electrode layer having at least three surfaces surrounded by a second intermixed layer, wherein the second intermixed layer comprises the first material and a fifth material, wherein the first gate electrode layer and the second gate electrode layer are disposed between two adjacent dielectric spacers.

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 and device are provided, wherein the method includes forming a stack including nanostructure channels, interposers, and a hard mask structure by forming a source/drain opening. The method further includes forming a sacrificial gate structure on the stack, and forming a spacer layer adjacent the sacrificial gate structure. The method further includes releasing the nanostructure channels by removing the interposers, and forming a gate dielectric on the nanostructure channels and a side surface of the spacer layer. The method also includes forming a reduced gate dielectric by removing a portion of the gate dielectric from the side surface of the spacer layer, the portion being laterally adjacent to the nanostructure channels, and forming a gate metal layer on the reduced gate dielectric and exposed portions of the spacer layer.

Abstract: A device includes a stack of first nanostructures; a first insulating layer adjacent to the stack of first nanostructures; a first source/drain region over the first insulating layer, wherein the first source/drain region includes a first semiconductor layer extending continuously over the sidewalls of the first nanostructures, wherein the first semiconductor layer is a first semiconductor material and a second semiconductor layer on the first semiconductor layer, wherein the second semiconductor layer is a second semiconductor material different from the first semiconductor material.

Abstract: A device includes a stack of first nanostructures; a first insulating layer adjacent to the stack of first nanostructures; and a first source/drain region over the first insulating layer, wherein the first source/drain region includes: first semiconductor layers, wherein each first semiconductor layer covers a sidewall of a respective first nanostructure, wherein the first semiconductor layers includes a first semiconductor material; second semiconductor layers, wherein each second semiconductor layer covers a sidewall of a respective first semiconductor layer, wherein the second semiconductor layers includes a second semiconductor material different from the first semiconductor material; and a third semiconductor layer on the second semiconductor layer, wherein the third semiconductor layer is a third semiconductor material different from the first semiconductor material and different from the second semiconductor material.

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 of forming a semiconductor device includes forming a fin of alternating layers of semiconductor nanostructures and sacrificial layers, laterally etching sidewall portions of the sacrificial layers, and depositing additional semiconductor material over the sidewalls of the semiconductor nanostructures and sacrificial layers. Following deposition of a dielectric material over the additional semiconductor material and additional etching, the remaining portions of the semiconductor structures and additional semiconductor material collectively form a hammer shape at each opposing side of the fin. Epitaxial source/drain regions formed on the opposing sides of the fin will contact the heads of the hammer shapes.

Abstract: Semiconductor structures and methods for forming the same are provided. The semiconductor structure includes a plurality of first nanostructures over a substrate, and a plurality of second nanostructures adjacent to the first nanostructures. The semiconductor structure includes a protective layer over the first nanostructures, and a first gate structure formed on the first nanostructures. The semiconductor structure includes a second gate structure formed on the second nanostructures. The semiconductor structure includes a first dielectric wall between the first gate structure and the second gate structure, and a top surface of the first dielectric wall is higher than a top surface of the protective layer.

Abstract: A method of forming a fin field effect transistor (finFET) on a substrate includes forming a fin structure on the substrate and forming a shallow trench isolation (STI) region on the substrate. First and second fin portions of the fin structure extend above a top surface of the STI region. The method further includes oxidizing the first fin portion to convert a first material of the first fin portion to a second material. The second material is different from the first material of the first fin portion and a material of the second fin portion. The method further includes forming an oxide layer on the oxidized first fin portion and the second fin portion and forming first and second polysilicon structures on the oxide layer.

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 a semiconductor substrate, a first semiconductor stack, a second semiconductor stack, a first gate structure, and a second gate structure. The semiconductor substrate comprising a first device region and a second device region. The first semiconductor stack is located on the semiconductor substrate over the first device region, and has first channels. The second semiconductor stack is located on the semiconductor substrate over the second device region, and has second channels. A total number of the first channels is greater than a total number of the second channels. The first gate structure encloses the first semiconductor stack. The second gate structure encloses the second semiconductor stack.

Abstract: A semiconductor structure includes a first stack of active channel layers and a second stack of active channel layers disposed over a semiconductor substrate, where the second stacking include a dummy channel layer and the first stack is free of any dummy channel layer, a gate structure engaged with the first stack and the second stack, and first S/D features disposed adjacent to the first stack and second S/D features disposed adjacent to the second stack, where the second S/D features overlap with the dummy channel layer.

Abstract: A method for manufacturing a semiconductor structure is provided. The method includes forming a fin structure protruding from a substrate, wherein the fin structure includes first semiconductor material layers and second semiconductor material layers alternately stacked. The method includes forming a dummy gate structure across the fin structure. The method includes forming a gate spacer on the sidewall of the dummy gate structure. The method includes removing the dummy gate structure to expose the fin structure. The method includes partially removing the second semiconductor material layers to form concave portions on sidewalls of the second semiconductor material layers. The method includes forming dielectric spacers in the concave portions. The method includes removing the first semiconductor material layers to form gaps. The method includes forming a gate structure in the gaps to wrap around the second semiconductor material layers and the dielectric spacers.

Abstract: A method for manufacturing a semiconductor structure includes: forming stacks each including a first nanosheet layer and a second nanosheet layer; forming isolation features among the stacks; performing an ion implantation process such that top portions of the isolation features are formed into isolation protection elements; forming a gate structure, each of the stacks having two portions that are located at two opposite sides of the gate structure; removing the two portions of each of the stacks to form source/drain recesses such that the first nanosheet layer, the second nanosheet layer, and the stacks are respectively formed into a first nanosheet, a second nanosheet, and patterned stacks; forming source/drain portions respectively in the source/drain recesses; removing a dummy gate of the gate structure; removing the second nanosheet of each of the patterned stacks; and forming a gate electrode around the first nanosheet of each of the patterned stacks.

Abstract: A device includes a first vertical stack of nanostructures over a substrate, a second vertical stack of nanostructures over the substrate, a wall structure between and in direct contact with the first and second vertical stacks, a gate structure wrapping around three sides of the nanostructures and a source/drain region beside the first vertical stack of nanostructures.

Abstract: A device includes a substrate, a first semiconductor fin over the substrate extending in a first lateral direction, a first vertical stack of semiconductor nanosheets over the substrate extending in the first lateral direction, and an inactive fin between the first semiconductor fin and the first vertical stack extending in the first lateral direction. A first gate structure surrounds and covers the first semiconductor fin, and extends in a second lateral direction substantially perpendicular to the first lateral direction. A second gate structure surrounds and covers the first vertical stack, and extends in the second lateral direction.

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 device structure and a method for forming a semiconductor device structure are provided. The method includes forming a metal gate stack wrapped around multiple semiconductor nanostructures. The metal gate stack has a gate dielectric layer and a gate electrode, and the semiconductor nanostructures are adjacent to an epitaxial structure. The method also includes recessing the gate dielectric layer, and a protruding portion of the gate electrode protrudes from a top surface of the gate dielectric layer after the gate dielectric layer is recessed. The method further includes forming a protective structure over the epitaxial structure, and the protective structure laterally surrounds the protruding portion of the gate electrode. In addition, the method includes forming a conductive contact electrically connected to the epitaxial structure and penetrating through the protective structure.