Abstract: A method includes etching a semiconductor substrate to form a trench, with the semiconductor substrate having a sidewall facing the trench, and depositing a first semiconductor layer extending into the trench. The first semiconductor layer includes a first bottom portion at a bottom of the trench, and a first sidewall portion on the sidewall of the semiconductor substrate. The first sidewall portion is removed to reveal the sidewall of the semiconductor substrate. The method further includes depositing a second semiconductor layer extending into the trench, with the second semiconductor layer having a second bottom portion over the first bottom portion, and a second sidewall portion contacting the sidewall of the semiconductor substrate. The second sidewall portion is removed to reveal the sidewall of the semiconductor substrate.

Abstract: A semiconductor device includes a substrate. The semiconductor device includes a fin that is formed over the substrate and extends along a first direction. The semiconductor device includes a gate structure that straddles the fin and extends along a second direction perpendicular to the first direction. The semiconductor device includes a first source/drain structure coupled to a first end of the fin along the first direction. The gate structure includes a first portion protruding toward the first source/drain structure along the first direction. A tip edge of the first protruded portion is vertically above a bottom surface of the gate structure.

Abstract: A semiconductor device includes a plurality of channel layers vertically separated from one another. The semiconductor device also includes an active gate structure comprising a lower portion and an upper portion. The lower portion wraps around each of the plurality of channel layers. The semiconductor device further includes a gate spacer extending along a sidewall of the upper portion of the active gate structure. The gate spacer has a bottom surface. Moreover, a dummy gate dielectric layer is disposed between the gate spacer and a topmost channel layer of plurality of channel layers. The dummy gate dielectric layer is in contact with a top surface of the topmost channel layer, the bottom surface of the gate spacer, and the sidewall of the gate structure.

Abstract: A method of fabricating a semiconductor device is disclosed. The method includes forming semiconductor fins on a substrate. A first dummy gate is formed over the semiconductor fins. A recess is formed in the first dummy gate, and the recess is disposed between the semiconductor fins. A dummy fin material is formed in the recess. A portion of the dummy fin material is removed to expose an upper surface of the first dummy gate and to form a dummy fin. A second dummy gate is formed on the exposed upper surface of the first dummy gate.

Abstract: A method of fabricating a semiconductor structure includes selective use of a cladding layer during the fabrication process to provide critical dimension uniformity. The cladding layer can be formed before forming a recess in an active channel structure or can be formed after filling a recess in an active channel structure with dielectric material. These techniques can be used in semiconductor structures such as gate-all-around (GAA) transistor structures implemented in an integrated circuit.

Abstract: A semiconductor device includes a plurality of semiconductor layers vertically separated from one another. The semiconductor device includes a gate structure that comprises a lower portion and an upper portion, wherein the lower portion wraps around each of the plurality of semiconductor layers. The semiconductor device includes a gate spacer that extends along a sidewall of the upper portion of the gate structure and has a bottom surface. A portion of the bottom surface of the gate spacer and a top surface of a topmost one of the plurality of semiconductor layers form an angle that is less than 90 degrees.

Abstract: A method of forming a semiconductor device includes: forming a fin protruding above a substrate; forming isolation regions on opposing sides of the fin; forming a dummy gate electrode over the fin; removing lower portions of the dummy gate electrode proximate to the isolation regions, where after removing the lower portions, there is a gap between the isolation regions and a lower surface of the dummy gate electrode facing the isolation regions; filling the gap with a gate fill material; after filling the gap, forming gate spacers along sidewalls of the dummy gate electrode and along sidewalls of the gate fill material; and replacing the dummy gate electrode and the gate fill material with a metal gate.

Abstract: Provided are devices with replacement structures and methods for fabricating such structures. A method includes forming a layer over a semiconductor material having a top surface in a horizontal plane; forming a dummy structure over the layer, wherein the dummy structure has sidewall, wherein the dummy structure lies directly over a first region of the layer and over a first region of the semiconductor material under the first region of the layer, and wherein the dummy structure does not lie directly over a second region of the layer or over a second region of the semiconductor material under the second region of the layer, and removing the second region of the layer and forming a side edge of the first region of the layer, wherein the side edge forms an angle of from 90 to 100 degrees with the horizontal plane.

Abstract: A semiconductor device includes a substrate. The semiconductor device includes a fin that is formed over the substrate and extends along a first direction. The semiconductor device includes a gate structure that straddles the fin and extends along a second direction perpendicular to the first direction. The semiconductor device includes a first source/drain structure coupled to a first end of the fin along the first direction. The gate structure includes a first portion protruding toward the first source/drain structure along the first direction. A tip edge of the first protruded portion is vertically above a bottom surface of the gate structure.

Abstract: In a method of manufacturing a semiconductor device, a fin structure in which first semiconductor layers and second semiconductor layers are alternately stacked over a bottom fin structure protruding from a substrate, is formed. A sacrificial gate structure is formed over the fin structure. A source/drain region of the fin structure is etched, thereby forming a source/drain space. The first semiconductor layers are laterally etched through the source/drain space. An inner spacer is formed on an end of each of the etched first semiconductor layers. One or more epitaxial layers are formed in the source/drain space, and the sacrificial gate structure is replaced with a metal gate structure. A width of the source/drain space at a bottommost one of the first semiconductor layers is greater than a width of the source/drain space at one of the first semiconductor layers above the bottommost one of the first semiconductor layers.

Abstract: A semiconductor device includes a plurality of channel layers vertically separated from one another. The semiconductor device also includes an active gate structure comprising a lower portion and an upper portion. The lower portion wraps around each of the plurality of channel layers. The semiconductor device further includes a gate spacer extending along a sidewall of the upper portion of the active gate structure. The gate spacer has a bottom surface. Moreover, a dummy gate dielectric layer is disposed between the gate spacer and a topmost channel layer of plurality of channel layers. The dummy gate dielectric layer is in contact with a top surface of the topmost channel layer, the bottom surface of the gate spacer, and the sidewall of the gate structure.

Abstract: A cyclic process including an etching process, a passivation process, and a pumping out process is provided to prevent over etching of the sacrificial gate electrode, particularly when near a high-k dielectric feature. The cyclic process solves the problems of failed gate electrode layer at an end of channel region and enlarges filling windows for replacement gate structures, thus improving channel control. Compared to state-of-art solutions, embodiments of the present disclosure also enlarge volume of source/drain regions, thus improving device performance.

Abstract: A method of fabricating a semiconductor device is disclosed. The method includes forming semiconductor fins on a substrate. A first dummy gate is formed over the semiconductor fins. A recess is formed in the first dummy gate, and the recess is disposed between the semiconductor fins. A dummy fin material is formed in the recess. A portion of the dummy fin material is removed to expose an upper surface of the first dummy gate and to form a dummy fin. A second dummy gate is formed on the exposed upper surface of the first dummy gate.

Abstract: The disclosure is directed towards semiconductor devices and methods of manufacturing the semiconductor devices. The methods include forming fins in a device region and forming other fins in a multilayer stack of semiconductor materials in a multi-channel device region. A topmost nanostructure may be exposed in the multi-channel device region by removing a sacrificial layer from the top of the multilayer stack. Once removed, a stack of nanostructures are formed from the multilayer stack. A native oxide layer is formed to a first thickness over the topmost nanostructure and to a second thickness over the remaining nanostructures of the stack, the first thickness being greater than the second thickness. A gate dielectric is formed over the fins in the device region. A gate electrode is formed over the gate dielectric in the device region and surrounding the native oxide layer in the multi-channel device region.

Abstract: A device includes a fin protruding from a semiconductor substrate; a gate stack over and along a sidewall of the fin; a gate spacer along a sidewall of the gate stack and along the sidewall of the fin; an epitaxial source/drain region in the fin and adjacent the gate spacer; and a corner spacer between the gate stack and the gate spacer, wherein the corner spacer extends along the sidewall of the fin, wherein a first region between the gate stack and the sidewall of the fin is free of the corner spacer, wherein a second region between the gate stack and the gate spacer is free of the corner spacer.

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: The disclosure is directed towards semiconductor devices and methods of manufacturing the semiconductor devices. The methods include forming fins in a device region and forming other fins in a multilayer stack of semiconductor materials in a multi-channel device region. A topmost nanostructure may be exposed in the multi-channel device region by removing a sacrificial layer from the top of the multilayer stack. Once removed, a stack of nanostructures are formed from the multilayer stack. A native oxide layer is formed to a first thickness over the topmost nanostructure and to a second thickness over the remaining nanostructures of the stack, the first thickness being greater than the second thickness. A gate dielectric is formed over the fins in the device region. A gate electrode is formed over the gate dielectric in the device region and surrounding the native oxide layer in the multi-channel device region.

Abstract: Processes to form differently-pitched gate structures are provided. An example method includes providing a workpiece having a substrate and semiconductor fins spaced apart from one another by an isolation feature, depositing a gate material layer over the workpiece, forming a patterned hard mask over the gate material layer, the patterned hard mask including differently-pitched elongated features, performing a first etch process using the patterned hard mask as an etch mask through the gate material layer to form a trench, performing a second etch process using the patterned hard mask as an etch mask to extend the trench to a top surface of the isolation feature, and performing a third etch process using the patterned hard mask to extend the trench into the isolation feature. The first etch process includes use of carbon tetrafluoride and is free of use of oxygen gas.

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: A semiconductor device includes a plurality of semiconductor layers vertically separated from one another. The semiconductor device includes a gate structure that comprises a lower portion and an upper portion, wherein the lower portion wraps around each of the plurality of semiconductor layers. The semiconductor device includes a gate spacer that extends along a sidewall of the upper portion of the gate structure and has a bottom surface. A portion of the bottom surface of the gate spacer and a top surface of a topmost one of the plurality of semiconductor layers form an angle that is less than 90 degrees.