The present disclosure provides an integrated circuit device that comprises a semiconductor substrate having a top surface; a first and a second source/drain features over the semiconductor substrate; a first semiconductor layer extending in parallel with the top surface and connecting the first and the second source/drain features, the first semiconductor layer having a center portion and two end portions, each of the two end portions connecting the center portion and one of the first and second source/drain features; a first spacer over the two end portions of the first semiconductor layer; a second spacer vertically between the two end portions of the first semiconductor layer and the top surface; and a gate electrode wrapping around and engaging the center portion of the first semiconductor layer. The center portion has a thickness smaller than the two end portions.

A method is provided and includes operations below: forming a multilayer stack, wherein the multilayer stack includes multiple first semiconductor layers and multiple second semiconductor layers that are alternately stacked; forming a first source region and a first drain region on opposing sides of a first portion of the multilayer stack and forming a second source region and a second drain region on opposing sides of a second portion of the multilayer stack; removing the second semiconductor layers in the multilayer stack; forming a first gate region, corresponding to a first transistor, over the first portion of the multilayer stack; forming a first insulating layer above the first gate region; and forming a second gate region, corresponding to a second transistor, above the first insulating layer and over the second portion of the multilayer stack.

A method is provided and includes operations below: forming a multilayer stack, wherein the multilayer stack includes multiple first semiconductor layers and multiple second semiconductor layers that are alternately stacked; forming a first source region and a first drain region on opposing sides of a first portion of the multilayer stack and forming a second source region and a second drain region on opposing sides of a second portion of the multilayer stack; removing the second semiconductor layers in the multilayer stack; forming a first gate region, corresponding to a first transistor, over the first portion of the multilayer stack; forming a first insulating layer above the first gate region; and forming a second gate region, corresponding to a second transistor, above the first insulating layer and over the second portion of the multilayer stack.

A semiconductor device includes a semiconductor fin, a gate structure, source/drain structures, and a contact structure. The semiconductor fin extends from a substrate. The gate structure extends across the semiconductor fin. The source/drain structures are on opposite sides of the gate structure. The contact structure is over a first one of the source/drain structures. The contact structure includes a semiconductor contact and a metal contact over the semiconductor contact. The semiconductor contact has a higher dopant concentration than the first one of the source/drain structures. The first one of the source/drain structures includes a first portion and a second portion at opposite sides of the fin and interfacing the semiconductor contact.

A semiconductor device includes source/drain regions, a gate structure, a first gate spacer, and a dielectric material. The source/drain regions are over a substrate. The gate structure is laterally between the source/drain regions. The first gate spacer is on a first sidewall of the gate structure, and spaced apart from a first one of the source/drain regions at least in part by a void region. The dielectric material is between the first one of the source/drain regions and the void region. The dielectric material has a gradient ratio of a first chemical element to a second chemical element.

First and second active regions are doped with different types of impurities, and extend in a first direction and spaced apart from each other in a second direction. First and third gate structures, which are on the first active region and a first portion of the isolation layer between the first and second active regions, extend in the second direction and are spaced apart from each other in the first direction. Second and fourth gate structures, which are on the second active region and the first portion, extend in the second direction, are spaced apart from each other in the first direction, and face and are spaced apart from the first and third gate structures, respectively, in the second direction. First to fourth contacts are on portions of the first to fourth gate structures, respectively. The first and fourth contacts are connected, and the second and third contacts are connected.

A method is provided of forming a bipolar transistor device. The method comprises depositing a collector dielectric layer over a substrate in a collector active region, depositing a dielectric anti-reflective (DARC) layer over the collector dielectric layer, dry etching away a base opening in the DARC layer, and wet etching away a portion of the collector dielectric layer in the base opening to provide an extended base opening to the substrate. The method further comprises performing a base deposition to form a base epitaxy region in the extended base opening and extending over first and second portions of the DARC layer that remains as a result of the dry etching away the base opening in the DARC layer, and forming an emitter region over the base epitaxy region.

An integrated circuit with an MOS transistor abutting field oxide and a gate structure on the field oxide adjacent to the MOS transistor and a gap between an epitaxial source/drain and the field oxide is formed with a silicon dioxide-based gap filler in the gap. Metal silicide is formed on the exposed epitaxial source/drain region. A CESL is formed over the integrated circuit and a PMD layer is formed over the CESL. A contact is formed through the PMD layer and CESL to make an electrical connection to the metal silicide on the epitaxial source/drain region.

The present disclosure provides a method that includes providing a semiconductor substrate having a first region and a second region; forming a first gate within the first region and a second gate within the second region on the semiconductor substrate; forming first source/drain features of a first semiconductor material with an n-type dopant in the semiconductor substrate within the first region; forming second source/drain features of a second semiconductor material with a p-type dopant in the semiconductor substrate within the second region. The second semiconductor material is different from the first semiconductor material in composition. The method further includes forming first silicide features to the first source/drain features and second silicide features to the second source/drain features; and performing an ion implantation process of a species to both the first and second regions, thereby introducing the species to first silicide features and the second source/drain features.

Methods for forming a semiconductor device having dual Schottky barrier heights using a single metal and the resulting device are provided. Embodiments include providing a substrate having an n-FET region and a p-FET region, each region including a gate between source/drain regions; applying a mask over the n-FET region; selectively amorphizing a surface of the p-FET region source/drain regions while the n-FET region is masked; removing the mask; depositing a titanium-based metal over the n-FET and p-FET region source/drain regions; and microwave annealing.