Abstract: A method of fabricating a device includes providing a fin element in a device region and forming a dummy gate over the fin element. In some embodiments, the method further includes forming a source/drain feature within a source/drain region adjacent to the dummy gate. In some cases, the source/drain feature includes a bottom region and a top region contacting the bottom region at an interface interposing the top and bottom regions. In some embodiments, the method further includes performing a plurality of dopant implants into the source/drain feature. In some examples, the plurality of dopant implants includes implantation of a first dopant within the bottom region and implantation of a second dopant within the top region. In some embodiments, the first dopant has a first graded doping profile within the bottom region, and the second dopant has a second graded doping profile within the top region.

Abstract: A method includes providing a substrate having a first region and a second region, forming an active region over the first region, forming a first gate structure and a second gate structure over the active region, etching the first gate structure to form a first opening, and etching the second gate structure to form a second opening. An edge-to-edge distance between the first opening and the active region is smaller than an edge-to-edge distance between the second opening and the active region. The method further includes filling the first and second openings with a dielectric material.

Abstract: SRAM designs based on GAA transistors are disclosed that provide flexibility for increasing channel widths of transistors at scaled IC technology nodes and relax limits on SRAM performance optimization imposed by FinFET-based SRAMs. GAA-based SRAM cells described have active region layouts with active regions shared by pull-down GAA transistors and pass-gate GAA transistors. A width of shared active regions that correspond with the pull-down GAA transistors are enlarged with respect to widths of the shared active regions that correspond with the pass-gate GAA transistors. A ratio of the widths is tuned to obtain ratios of pull-down transistor effective channel width to pass-gate effective channel width greater than 1, increase an on-current of pull-down GAA transistors relative to an on-current of pass-gate GAA transistors, decrease a threshold voltage of pull-down GAA transistors relative to a threshold voltage of pass-gate GAA transistors, and/or increases a ? ratio of an SRAM cell.

Abstract: Methods of forming a semiconductor device are provided. A method according to the present disclosure includes forming, over a workpiece, a dummy gate stack comprising a first semiconductor material, depositing a first dielectric layer over the dummy gate stack using a first process, implanting the workpiece with a second semiconductor material different from the first semiconductor material, annealing the dummy gate stack after the implanting, and replacing the dummy gate stack with a metal gate stack.

Abstract: A semiconductor structure includes a first pair of source/drain features (S/D), a first stack of channel layers connected to the first pair of S/D, a second pair of S/D, and a second stack of channel layers connected to the second pair of S/D. The first pair of S/D each include a first epitaxial layer having a first dopant, a second epitaxial layer having a second dopant and disposed over the first epitaxial layer and connected to the first stack of channel layers, and a third epitaxial layer having a third dopant and disposed over the second epitaxial layer. The second pair of S/D each include a fourth epitaxial layer having a fourth dopant and connected to the second stack of channel layers, and a fifth epitaxial layer having a fifth dopant and disposed over the fourth epitaxial layer. The first dopant through the fourth dopant are of different species.

Abstract: A semiconductor structure includes a substrate, semiconductor layers, source/drain features, metal oxide layers, and a gate structure. The semiconductor layers are over the substrate and spaced apart from each other in a Z-direction. The source/drain features are over the substrate. The semiconductor layers are between the source/drain features. The metal oxide layers are on top surfaces and bottom surfaces of the semiconductor layers. The gate structure covers and is in contact with center portions of the metal oxide layers on top surfaces and bottom surfaces of the semiconductor layers.

Abstract: A method includes providing a substrate having a first region and a second region, forming a fin protruding from the first region, where the fin includes a first SiGe layer and a stack alternating Si layers and second SiGe layers disposed over the first SiGe layer and the first SiGe layer has a first concentration of Ge and each of the second SiGe layers has a second concentration of Ge that is greater than the first concentration, recessing the fin to form an S/D recess, recessing the first SiGe layer and the second SiGe layers exposed in the S/D recess, where the second SiGe layers are recessed more than the first SiGe layer, forming an S/D feature in the S/D recess, removing the recessed first SiGe layer and the second SiGe layers to form openings, and forming a metal gate structure over the fin and in the openings.

Abstract: A Static Radom Access Memory (SRAM) cell includes a pass-gate transistor and a pull-down transistor. The pass-gate transistor includes a first active region and a first gate structure engaging the first active region. The pull-down transistor includes a second active region and a second gate structure engaging the second active region. The SRAM cell further includes a first isolation feature abutting the first gate structure and a second isolation feature abutting the second gate structure. The first isolation feature is spaced from the first active region of the pass-gate transistor for a first distance. The second isolation feature is spaced from the second active region of the pull-down transistor for a second distance that is larger than the first distance.

Abstract: A semiconductor structure includes substrate, semiconductor layers, source/drain features, metal oxide layers, and a gate structure. The semiconductor layers extend in an X-direction and over the substrate. The semiconductor layers are spaced apart from each other in a Z-direction. The source/drain features are on opposite sides of the semiconductor layers in the X-direction. The metal oxide layers cover bottom surfaces of the semiconductor layers. The gate structure wraps around the semiconductor layers and the metal oxide layers. The metal oxide layers are in contact with the gate structure.

Abstract: SRAM designs based on GAA transistors are disclosed that provide flexibility for increasing channel widths of transistors at scaled IC technology nodes and relax limits on SRAM performance optimization imposed by FinFET-based SRAMs. GAA-based SRAM cells described have active region layouts with active regions shared by pull-down GAA transistors and pass-gate GAA transistors. A width of shared active regions that correspond with the pull-down GAA transistors are enlarged with respect to widths of the shared active regions that correspond with the pass-gate GAA transistors. A ratio of the widths is tuned to obtain ratios of pull-down transistor effective channel width to pass-gate effective channel width greater than 1, increase an on-current of pull-down GAA transistors relative to an on-current of pass-gate GAA transistors, decrease a threshold voltage of pull-down GAA transistors relative to a threshold voltage of pass-gate GAA transistors, and/or increases a ? ratio of an SRAM cell.

Abstract: A method includes forming a fin that includes a first semiconductor layers and a second semiconductor layers alternatively disposed; forming a gate stack on the fin and a gate spacer disposed on a sidewall of the gate stack; etching the fin within a source/drain region, resulting in a source/drain trench; recessing the first semiconductor layers in the source/drain trench, resulting in first recesses underlying the gate spacer; forming inner spacers in the first recesses; recessing the second semiconductor layers in the source/drain trench, resulting in second recesses; and epitaxially growing a source/drain feature in the source/drain trench, wherein the epitaxially growing further includes a first epitaxial semiconductor layer extending into the second recesses; and a second epitaxial semiconductor layer on the first epitaxial semiconductor layer and filling in the source/drain trench, wherein the first and second epitaxial semiconductor layers are different in composition.

Abstract: Semiconductor devices and methods are provided. A semiconductor device according to the present disclosure includes a first transistor having a first gate dielectric layer, a second transistor having a second gate dielectric layer, and a third transistor having a third gate dielectric layer. The first gate dielectric layer includes a first concentration of a dipole layer material, the second gate dielectric layer includes a second concentration of the dipole layer material, and the third gate dielectric layer includes a third concentration of the dipole layer material. The dipole layer material includes lanthanum oxide, aluminum oxide, or yittrium oxide. The first concentration is greater than the second concentration and the second concentration is greater than the third concentration.

Abstract: A method includes providing a substrate having a first region and a second region, forming a fin protruding from the first region, where the fin includes a first SiGe layer and a stack alternating Si layers and second SiGe layers disposed over the first SiGe layer and the first SiGe layer has a first concentration of Ge and each of the second SiGe layers has a second concentration of Ge that is greater than the first concentration, recessing the fin to form an S/D recess, recessing the first SiGe layer and the second SiGe layers exposed in the S/D recess, where the second SiGe layers are recessed more than the first SiGe layer, forming an S/D feature in the S/D recess, removing the recessed first SiGe layer and the second SiGe layers to form openings, and forming a metal gate structure over the fin and in the openings.

Abstract: A device includes a first and a second stacks of channel layers each extending from a first height to a second height. A first dielectric feature on a first side of the first stack and between the first and the second stacks extends from a third height to a fourth height. A second dielectric feature on a second side of the first stack opposite to the first side extends from the third height to a fifth height. A gate electrode extends continuously across a top surface of the first and the second stacks and extends to a sixth height. The fifth height is above the sixth height, the sixth height is above the second height, the second height is above the fourth height, the fourth height is above the first height, and the first height is above the third height.

Abstract: Methods of forming a semiconductor device are provided. A method according to the present disclosure includes forming, over a workpiece, a dummy gate stack comprising a first semiconductor material, depositing a first dielectric layer over the dummy gate stack using a first process, implanting the workpiece with a second semiconductor material different from the first semiconductor material, annealing the dummy gate stack after the implanting, and replacing the dummy gate stack with a metal gate stack.

Abstract: A semiconductor structure includes a first pair of source/drain features (S/D), a first stack of channel layers connected to the first pair of S/D, a second pair of S/D, and a second stack of channel layers connected to the second pair of S/D. The first pair of S/D each include a first epitaxial layer having a first dopant, a second epitaxial layer having a second dopant and disposed over the first epitaxial layer and connected to the first stack of channel layers, and a third epitaxial layer having a third dopant and disposed over the second epitaxial layer. The second pair of S/D each include a fourth epitaxial layer having a fourth dopant and connected to the second stack of channel layers, and a fifth epitaxial layer having a fifth dopant and disposed over the fourth epitaxial layer. The first dopant through the fourth dopant are of different species.

Abstract: A device includes a first and a second stacks of channel layers each extending from a first height to a second height. A first dielectric feature on a first side of the first stack and between the first and the second stacks extends from a third height to a fourth height. A second dielectric feature on a second side of the first stack opposite to the first side extends from the third height to a fifth height. A gate electrode extends continuously across a top surface of the first and the second stacks and extends to a sixth height. The fifth height is above the sixth height, the sixth height is above the second height, the second height is above the fourth height, the fourth height is above the first height, and the first height is above the third height.

Abstract: Gate structures having neutral zones to minimize metal gate boundary effects and methods of fabricating thereof are disclosed herein. An exemplary metal gate includes a first portion, a second portion, and a third portion. The second portion is disposed between the first portion and the third portion. The first portion includes a first gate dielectric layer, a first p-type work function layer, and a first n-type work function layer. The second portion includes a second gate dielectric layer and a second p-type work function layer. The third portion includes a third gate dielectric layer, a third p-type work function, and a second n-type work function layer. The second p-type work function layer separates the first n-type work function layer from the second n-type work function layer, such that the first n-type work function layer does not share an interface with the second n-type work function layer.

Abstract: Methods of forming a semiconductor device are provided. A method according to the present disclosure includes forming, over a workpiece, a dummy gate stack comprising a first semiconductor material, depositing a first dielectric layer over the dummy gate stack using a first process, implanting the workpiece with a second semiconductor material different from the first semiconductor material, annealing the dummy gate stack after the implanting, and replacing the dummy gate stack with a metal gate stack.

Abstract: A semiconductor device includes a substrate, two source/drain features over the substrate, channel layers connecting the two source/drain features, and a gate structure wrapping around each of the channel layers. Each of the two source/drain features include a first epitaxial layer, a second epitaxial layer over the first epitaxial layer, and a third epitaxial layer on inner surfaces of the second epitaxial layer. The channel layers directly interface with the second epitaxial layers and are separated from the third epitaxial layers by the second epitaxial layers. The first epitaxial layers include a first semiconductor material with a first dopant. The second epitaxial layers include the first semiconductor material with a second dopant. The second dopant has a higher mobility than the first dopant.