Abstract: A device includes a first channel layer, a second channel layer, a gate structure, a source/drain epitaxial structure, and a source/drain contact. The first channel layer and the second channel layer are arranged above the first channel layer in a spaced apart manner over a substrate. The gate structure surrounds the first and second channel layers. The source/drain epitaxial structure is connected to the first and second channel layers. The source/drain contact is connected to the source/drain epitaxial structure. The second channel layer is closer to the source/drain contact than the first channel layer is to the source/drain contact, and the first channel layer is thicker than the second channel layer.

Abstract: A device includes a first channel layer, a second channel layer, a gate structure, a source/drain epitaxial structure, and a source/drain contact. The first channel layer and the second channel layer are arranged above the first channel layer in a spaced apart manner over a substrate. The gate structure surrounds the first and second channel layers. The source/drain epitaxial structure is connected to the first and second channel layers. The source/drain contact is connected to the source/drain epitaxial structure. The second channel layer is closer to the source/drain contact than the first channel layer is to the source/drain contact, and the first channel layer is thicker than the second channel layer.

Abstract: A device includes a semiconductor nanostructure, and an oxide layer, which includes horizontal portions on a top surface and a bottom surface of the semiconductor nanostructure, vertical portions on sidewalls of the semiconductor nanostructure, and corner portions on corners of the semiconductor nanostructure. The horizontal portions have a first thickness. The vertical portions have a second thickness. The corner portions have a third thickness. Both of the second thickness and the third thickness are greater than the first thickness. A high-k dielectric layer surrounds the oxide layer. A gate electrode surrounds the high-k dielectric layer.

Abstract: A device includes a semiconductor nanostructure, and an oxide layer, which includes horizontal portions on a top surface and a bottom surface of the semiconductor nanostructure, vertical portions on sidewalls of the semiconductor nanostructure, and corner portions on corners of the semiconductor nanostructure. The horizontal portions have a first thickness. The vertical portions have a second thickness. The corner portions have a third thickness. Both of the second thickness and the third thickness are greater than the first thickness. A high-k dielectric layer surrounds the oxide layer. A gate electrode surrounds the high-k dielectric layer.

Abstract: A method of forming a nanostructure field-effect transistor (nano-FET) device includes: forming a fin structure that includes a fin and alternating layers of a first semiconductor material and a second semiconductor material overlying the fin; forming a dummy gate structure over the fin structure; forming source/drain regions over the fin structure on opposing sides of the dummy gate structure; removing the dummy gate structure to expose the first and second semiconductor materials under the dummy gate structure; selectively removing the exposed first semiconductor material, where after the selectively removing, the exposed second semiconductor material remains to form nanostructures, where different surfaces of the nanostructures have different atomic densities of the second semiconductor material; forming a gate dielectric layer around the nanostructures, thicknesses of the gate dielectric layer on the different surfaces of the nanostructures being formed substantially the same; and forming a gate electrode

Abstract: A device includes a first channel layer, a second channel layer, a gate structure, a source/drain epitaxial structure, and a source/drain contact. The first channel layer and the second channel layer are arranged above the first channel layer in a spaced apart manner over a substrate. The gate structure surrounds the first and second channel layers. The source/drain epitaxial structure is connected to the first and second channel layers. The source/drain contact is connected to the source/drain epitaxial structure. The second channel layer is closer to the source/drain contact than the first channel layer is to the source/drain contact, and the first channel layer is thicker than the second channel layer.

Abstract: A device includes a semiconductor nanostructure, and an oxide layer, which includes horizontal portions on a top surface and a bottom surface of the semiconductor nanostructure, vertical portions on sidewalls of the semiconductor nanostructure, and corner portions on corners of the semiconductor nanostructure. The horizontal portions have a first thickness. The vertical portions have a second thickness. The corner portions have a third thickness. Both of the second thickness and the third thickness are greater than the first thickness. A high-k dielectric layer surrounds the oxide layer. A gate electrode surrounds the high-k dielectric layer.