Semiconductor device and the manufacturing method thereof are disclosed herein. An exemplary semiconductor device comprises a substrate, at least two gate structures disposed over the substrate, each of the at least two gate structures including a gate electrode and a spacer disposed along sidewalls of the gate electrode, wherein the spacer includes a refill portion and a bottom portion, the refill portion of the spacer has a funnel shape such that a top surface of the refill portion of the spacer is larger than a bottom surface of the refill portion of the spacer, and a source/drain contact disposed over the substrate and between the spacers of the at least two gate structures.

A method of fabricating semiconductor fins, including, patterning a film stack to produce one or more sacrificial mandrels having sidewalls, exposing the sidewall on one side of the one or more sacrificial mandrels to an ion beam to make the exposed sidewall more susceptible to oxidation, oxidizing the opposite sidewalls of the one or more sacrificial mandrels to form a plurality of oxide pillars, removing the one or more sacrificial mandrels, forming spacers on opposite sides of each of the plurality of oxide pillars to produce a spacer pattern, removing the plurality of oxide pillars, and transferring the spacer pattern to the substrate to produce a plurality of fins.

A semiconductor device includes: an isolation insulating layer; fin structures protruding from the isolation insulating layer; gate structures, each having a metal gate and a cap insulating layer disposed over the metal gate; a first source/drain epitaxial layer and a second source/drain epitaxial layer disposed between two adjacent gate structures; and a first conductive contact disposed on the first source/drain epitaxial layer, and a second conductive contact disposed on the second source/drain epitaxial layer; a separation isolation region disposed between the first and second conductive contact; and an insulating layer disposed between the separation isolation region and the isolation insulating layer. The separation isolation region is made of a different material than the insulating layer.

A structure includes a substrate, an isolation structure over the substrate, a fin extending from the substrate and adjacent to the isolation structure, two source/drain (S/D) features over the fin, channel layers suspended over the substrate and connecting the S/D features, a first gate structure wrapping around each of the channel layers in the stack, two outer spacers disposed on two opposing sidewalls of the first gate structure that are on outer surfaces of the stack, inner spacers disposed between the S/D features and the channel layers, and a gate-end dielectric feature over the isolation structure and directly contacting an end of the gate structure. The gate-end dielectric feature includes a first material of a dielectric constant that is higher than dielectric constants of materials included in the outer spacers and the inner spacers.

A semiconductor device structure, along with methods of forming such, are described. The structure includes a plurality of semiconductor layers and a first source/drain epitaxial feature in contact with the plurality of semiconductor layers. The first source/drain epitaxial feature includes a bottom portion having substantially straight sidewalls. The structure further includes a spacer having a gate spacer portion and one or more source/drain spacer portions. Each source/drain spacer portion has a first height, and a source/drain spacer portion of the one or more source/drain spacer portions is in contact with one of the substantially straight sidewalls of the first source/drain epitaxial feature. The structure further includes a dielectric feature disposed adjacent one source/drain spacer portion of the one or more source/drain spacer portion. The dielectric has a second height substantially greater than the first height.

A semiconductor device may include first channels on a first region of a substrate and spaced apart from each other in a vertical direction substantially perpendicular to an upper surface of the substrate, second channels on a second region of the substrate and spaced apart from each other in the vertical direction, a first gate structure on the first region of the substrate and covering at least a portion of a surface of each of the first channels, and a second gate structure on the second region of the substrate and covering at least a portion of a surface of each of the second channels. The second channels may be disposed at heights substantially the same as those of corresponding ones of the first channels, and a height of a lowermost one of the second channels may be greater than a height of a lowermost one of the first channels.

A method for smoothing a surface of a semiconductor portion is disclosed. In the method, an intentional oxide layer is formed on the surface of the semiconductor portion, a treated layer is formed in the semiconductor portion and inwardly of the intentional oxide layer, and then, the intentional oxide layer and the treated layer are removed to obtain a smoothed surface. The method may also be used for widening a recess in a manufacturing process for a semiconductor structure.

A method of manufacturing an integrated circuit device including a self-aligned air spacer including the operations of forming a dummy gate, forming a sidewall on the dummy gate, forming a dummy layer on the sidewall, constructing a gate structure within an opening defined by the sidewall, removing at least a portion of the first dummy layer to form a first recess between the sidewall layer and the dummy gate, and capping the first recess to form a first air spacer.

A method includes depositing a multi-layer stack over a semiconductor substrate, the multi-layer stack including a plurality of sacrificial layers that alternate with a plurality of channel layers; forming a first recess in the multi-layer stack; forming first spacers on sidewalls of the sacrificial layers in the first recess; depositing a first semiconductor material in the first recess, where the first semiconductor material is undoped, where the first semiconductor material is in physical contact with a sidewall and a bottom surface of at least one of the first spacers; implanting dopants in the first semiconductor material, where after implanting dopants the first semiconductor material has a gradient-doped profile; and forming an epitaxial source/drain region in the first recess over the first semiconductor material, where a material of the epitaxial source/drain region is different from the first semiconductor material.

A device includes a substrate including an active region, a gate stack over the active region, and a hard mask over the gate stack. The hard mask includes a capping layer, a buttress layer extending along sidewalls and a bottom of the capping layer, and a liner layer extending along sidewalls and a bottom of the buttress layer. The buttress layer includes a metal oxide material or a metal nitride material.