An integrated circuit includes a substrate, at least one n-type semiconductor device, and at least one p-type semiconductor device. The n-type semiconductor device is present on the substrate. The n-type semiconductor device includes a gate structure having a bottom surface and at least one sidewall. The bottom surface of the gate structure of the n-type semiconductor device and the sidewall of the gate structure of the n-type semiconductor device intersect to form an interior angle. The p-type semiconductor device is present on the substrate. The p-type semiconductor device includes a gate structure having a bottom surface and at least one sidewall. The bottom surface of the gate structure of the p-type semiconductor device and the sidewall of the gate structure of the p-type semiconductor device intersect to form an interior angle smaller than the interior angle of the gate structure of the n-type semiconductor device.

In an embodiment, a device includes: a semiconductor substrate; a first fin extending from the semiconductor substrate; a second fin extending from the semiconductor substrate; an epitaxial source/drain region including: a main layer in the first fin and the second fin, the main layer including a first semiconductor material, the main layer having an upper faceted surface and a lower faceted surface, the upper faceted surface and the lower faceted surface each being raised from respective surfaces of the first fin and the second fin; and a semiconductor contact etch stop layer (CESL) contacting the upper faceted surface and the lower faceted surface of the main layer, the semiconductor CESL including a second semiconductor material, the second semiconductor material being different from the first semiconductor material.

A semiconductor device structure is provided. The semiconductor device structure includes a substrate having a base and a fin over the base. The semiconductor device structure includes a nanostructure over the fin. The semiconductor device structure includes a gate stack wrapping around an upper portion of the fin and the nanostructure. The semiconductor device structure includes an inner spacer between the fin and the nanostructure. The semiconductor device structure includes a film in the inner spacer. A first dielectric constant of the film is lower than a second dielectric constant of the inner spacer. The semiconductor device structure includes a low dielectric constant structure in the film.

Gate-all-around integrated circuit structures having germanium-doped nanowire/nanoribbon channel structures, and methods of fabricating gate-all-around integrated circuit structures having germanium-doped nanowire/nanoribbon channel structures, are described. For example, an integrated circuit structure includes a vertical arrangement of nanowires above a substrate. Individual ones of the vertical arrangement of nanowires have a relatively higher germanium concentration at a lateral mid-point of the nanowire than at lateral ends of the nanowire.

Confined epitaxial regions for semiconductor devices and methods of fabricating semiconductor devices having confined epitaxial regions are described. For example, a semiconductor structure includes a plurality of parallel semiconductor fins disposed above and continuous with a semiconductor substrate. An isolation structure is disposed above the semiconductor substrate and adjacent to lower portions of each of the plurality of parallel semiconductor fins. An upper portion of each of the plurality of parallel semiconductor fins protrudes above an uppermost surface of the isolation structure. Epitaxial source and drain regions are disposed in each of the plurality of parallel semiconductor fins adjacent to a channel region in the upper portion of the semiconductor fin. The epitaxial source and drain regions do not extend laterally over the isolation structure. The semiconductor structure also includes one or more gate electrodes, each gate electrode disposed over the channel region of one or more of the plurality of parallel semiconductor fins.

Methods and structures for forming strained-channel finFETs are described. Fin structures for finFETs may be formed in two epitaxial layers that are grown over a bulk substrate. A first thin epitaxial layer may be cut and used to impart strain to an adjacent channel region of the finFET via elastic relaxation. The structures exhibit a preferred design range for increasing induced strain and uniformity of the strain over the fin height.

A fin-type field effect transistor comprising a substrate, at least one gate stack and epitaxy material portions is described. The substrate has fins and insulators located between the fins, and the fins include channel portions and flank portions beside the channel portions. The at least one gate stack is disposed over the insulators and over the channel portions of the fins. The epitaxy material portions are disposed over the flank portions of the fins and at two opposite sides of the at least one gate stack. The epitaxy material portions disposed on the flank portions of the fins are separate from one another.

An integrated circuits (IC) includes a standard cell array and a SRAM cell array. The standard cell array includes standard cells having first P-type transistors arranged in a first column of the standard cell array and a first fin structure shared by the first P-type transistors. The SRAM cell array includes SRAM cells having second P-type transistors arranged in a second column of the SRAM cell array and second fin structures arranged in the second column. Each of the second fin structures is shared by two adjacent second P-type transistors respectively disposed in two adjacent SRAM cells. A material of the first fin structure is different from a material of the second fin structures. A dimension of the first fin structure along the first column is greater than a dimension of each of the second fin structures along the second column.

The present disclosure provides a semiconductor device with a plurality of semiconductor channel layers. The semiconductor channel layers include a first semiconductor layer and a second semiconductor layer disposed over the first semiconductor layer. A strain in the second semiconductor layer is different from a strain in the first semiconductor layer. A gate is disposed over the plurality of semiconductor channel layers.

A FinFET including a gate stack, a semiconductor fin embedded in the gate stack, a source and a drain disposed is provided. The semiconductor fin extends along a widthwise direction of the gate stack and has a first concave and a second concave exposed at sidewalls of the gate stack respectively. The source and drain are disposed at two opposite sides of the gate stack. The source includes a first portion in contact with and embedded in the first concave. The drain includes a second portion in contact with and embedded in the second concave. The first portion and the second portion are covered by the gate stack.