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. 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 comprises a first layer and a second layer. The first layer is in contact with a first portion of the sidewall and the second layer is in contact with a second portion of the sidewall.

A semiconductor structure and a method of forming the same are provided. In an embodiment, an exemplary semiconductor structure includes a gate structure. The gate structure includes a gate dielectric layer, an n-type work function layer embedded in the gate dielectric layer, a dielectric capping layer embedded in the n-type work function layer, and a p-type work function layer embedded in the dielectric capping layer. A top surface of the gate structure exposes the n-type work function layer, the dielectric capping layer, and the p-type work function layer. The semiconductor structure also includes a first metal cap on the n-type work function layer and a second metal cap on the p-type work function layer. The first metal cap is spaced apart from the second metal cap. without formed on the dielectric capping layer.

A multiple gate dielectrics and dual work-functions field effect transistor (MGO-DWF-FET) is provided on an active region of a semiconductor substrate. The MGO-DWF-FET includes a first functional gate structure including a U-shaped first high-k gate dielectric material layer and a first work-function metal-containing structure, and a laterally adjacent, and contacting, second functional gate structure that includes a U-shaped second high-k gate dielectric material layer and a second work-function metal-containing structure. The first functional gate structure has a gate length that differs from a gate length of the second functional gate structure.

In an example, a method includes depositing a first sidewall spacer layer over a substrate having a layer stack including alternating layers of a nanosheet and a sacrificial layer, and a dummy gate formed over the layer stack, the first sidewall spacer layer formed over the dummy gate. The method includes depositing a metal-containing liner over the first sidewall spacer layer; forming a first sidewall spacer along the dummy gate by anisotropically etching the metal-containing liner and the first sidewall spacer layer; performing an anisotropic etch back process to form a plurality of vertical recesses in the layer stack; laterally etching the layer stack and form a plurality of lateral recesses between adjacent nanosheets; depositing a second sidewall spacer layer to fill the plurality of lateral recesses; and etching a portion of the second sidewall spacer layer to expose tips of the nanosheet layers.

An integrated circuit includes a nanosheet transistor having a plurality of stacked channels, a gate electrode surrounding the stacked channels, a source/drain region, and a source/drain contact. The integrated circuit includes a first dielectric layer between the gate metal and the source/drain contact, a second dielectric layer on the first dielectric layer, and a cap metal on the first gate metal and on a hybrid fin structure. The second dielectric layer is on the hybrid fin structure between the cap metal and the source/drain contact.

A method for forming a semiconductor device structure is provided. The semiconductor device includes forming nanowire structures stacked over a substrate and spaced apart from one another, and forming a dielectric material surrounding the nanowire structures. The dielectric material has a first nitrogen concentration. The method also includes treating the dielectric material to form a treated portion. The treated portion of the dielectric material has a second nitrogen concentration that is greater than the first nitrogen concentration. The method also includes removing the treating portion of the dielectric material, thereby remaining an untreated portion of the dielectric material as inner spacer layers; and forming the gate stack surrounding nanowire structures and between the inner spacer layers.

A device includes a semiconductor substrate, a channel layer, a gate structure, source/drain epitaxial structures, and a dielectric isolation layer. The channel layer is over the semiconductor substrate. The gate structure is over the semiconductor substrate and surrounds the channel layer. The source/drain epitaxial structures are connected to the channel layer and arranged in a first direction. The dielectric isolation layer is between the gate structure and the semiconductor substrate. The dielectric isolation layer is wider than the gate structure but narrower than the channel layer in the first direction.

The present disclosure describes a semiconductor device and methods for forming the same. The semiconductor device includes nanostructures on a substrate and a source/drain region in contact with the nanostructures. The source/drain region includes epitaxial end caps, where each epitaxial end cap is formed at an end portion of a nanostructure of the nanostructures. The source/drain region also includes an epitaxial body in contact with the epitaxial end caps and an epitaxial top cap formed on the epitaxial body. The semiconductor device further includes gate structure formed on the nanostructures.

In a method of manufacturing a semiconductor device, a fin structure including a stacked layer of first and second semiconductor layers and a hard mask layer over the stacked layer is formed. A sacrificial cladding layer is formed over at least sidewalls of the exposed hard mask layer and stacked layer. An etching is performed to remove lateral portions of the sacrificial cladding layer, thereby leaving the sacrificial cladding layer on sidewalls of the exposed hard mask layer and stacked layer. A first dielectric layer and a second dielectric layer made of a different material than the first dielectric layer are formed. The second dielectric layer is recessed, and a third dielectric layer made of a different material than the second dielectric layer is formed on the recessed second dielectric layer. During the etching operation, a protection layer is formed over the sacrificial cladding layer.

A device includes a diode that includes a first group III-nitride (III-N) material and a transistor adjacent to the diode, where the transistor includes the first III-N material. The diode includes a second III-N material, a third III-N material between the first III-N material and the second III-N material, a first terminal including a metal in contact with the third III-N material, a second terminal coupled to the first terminal through the first group III-N material. The device further includes a transistor structure, adjacent to the diode structure. The transistor structure includes the first, second, and third III-N materials, a source and drain, a gate electrode and a gate dielectric between the gate electrode and each of the first, second and third III-N materials.