Gate-all-around integrated circuit structures having embedded GeSnB source or drain structures, and methods of fabricating gate-all-around integrated circuit structures having embedded GeSnB source or drain structures, are described. For example, an integrated circuit structure includes a vertical arrangement of horizontal nanowires above a fin, the fin including a defect modification layer on a first semiconductor layer, and a second semiconductor layer on the defect modification layer. A gate stack is around the vertical arrangement of horizontal nanowires. A first epitaxial source or drain structure is at a first end of the vertical arrangement of horizontal nanowires, and a second epitaxial source or drain structure is at a second end of the vertical arrangement of horizontal nanowires.

A method includes depositing a silicon layer, which includes first portions over a plurality of strips, and second portions filled into trenches between the plurality of strips. The plurality of strips protrudes higher than a base structure. The method further includes performing an anneal to allow parts of the first portions of the silicon layer to migrate toward lower parts of the plurality of trenches, and performing an etching on the silicon layer to remove some portions of the silicon layer.

The present disclosure relates to a semiconductor device including a substrate having a top surface and a gate stack. The gate stack includes a gate dielectric layer on the substrate and a gate electrode on the gate dielectric layer. The semiconductor device also includes a multi-spacer structure. The multi-spacer includes a first spacer formed on a sidewall of the gate stack, a second spacer, and a third spacer. The second spacer includes a first portion formed on a sidewall of the first spacer and a second portion formed on the top surface of the substrate. The second portion of the second spacer has a thickness in a first direction that gradually decreases. The third spacer is formed on the second portion of the second spacer and on the top surface of the substrate. The semiconductor device further includes a source/drain region formed in the substrate, and a portion of the third spacer abuts the source/drain region and the second portion of the second spacer.

A semiconductor device structure includes a source/drain feature comprising a first surface, a second surface opposing the first surface, and a sidewall connecting the first surface to the second surface. The structure also includes a dielectric layer having a continuous surface in contact with the entire second surface of the source/drain feature, a semiconductor layer having a first surface, a second surface opposing the first surface, and a sidewall connecting the first surface to the second surface, wherein the sidewall of the semiconductor layer is in contact with the sidewall of the source/drain feature. The structure also includes a gate dielectric layer in contact with the continuous surface of the dielectric layer and the second surface of the semiconductor layer, and a gate electrode layer surrounding a portion of the semiconductor layer.

A method of manufacturing a semiconductor device includes forming a semiconductor structure extending from a substrate in a first direction and having first and second regions; forming a sacrificial gate pattern intersecting the first region of the semiconductor structure and extending in a second direction perpendicular to the first direction; reducing a width in the second direction of the second region of the semiconductor structure exposed to at least one side of the sacrificial gate pattern; forming at least one recess portion by removing a portion of the second region of the semiconductor structure; forming one or more source/drain regions in the recess portion of the semiconductor structure on at least one side of the sacrificial gate pattern; forming at least one gap region by removing the sacrificial gate pattern; and forming a gate structure by depositing a gate dielectric layer and a gate electrode in the gap region.

A semiconductor device is provided. The semiconductor device includes a semiconductor fin over a substrate, and a gate structure along sidewalls and the top surface of the semiconductor fin. The gate structure covers the first portion of the semiconductor fin. The semiconductor device also includes a source/drain feature adjacent to the gate structure. The semiconductor device further includes a source/drain contact connected to the source/drain feature. The source/drain contact extends downwards to a position that is lower than the top surface of the first portion of the semiconductor fin.

An epitaxial growth process for a semiconductor device includes providing a semiconductor substrate, forming a plurality of Dummy Gate structures on the surface of the semiconductor substrate, and forming grooves in a self-aligned manner on both sides of the Dummy Gate structures; forming an initial seed layer on the inner side surfaces of the grooves, the thickness of the formed initial seed layer on the bottoms of the grooves being greater and the thickness of the formed initial seed layer on the sidewalls being smaller since the growth speed of crystal faces <100> and <110> is different; longitudinally etching the initial seed layer to thin the bottom of the initial seed layer to form a seed layer; forming a main body layer on the seed layer, the main body layer filling the grooves; and forming a cover layer on the main body layer.

A method includes forming a first and a second contact opening to reveal a first and a second source/drain region, respectively, forming a mask layer having a first and a second portion in the first and the second contact openings, respectively, forming a first and a second sacrificial ILD in the first and the second contact openings, respectively, removing the first sacrificial ILD from the first contact opening, filling a filler in the first contact opening, and etching the second sacrificial ILD. The filler protects the first portion of the mask layer from being etched. An ILD is formed in the second contact opening and on the second portion of the mask layer. The filler and the first portion of the mask layer are removed using a wet etch to reveal the first contact opening. A contact plug is formed in the first contact opening.

Semiconductor devices and methods of fabricating the semiconductor devices are described herein. The method includes steps for patterning fins in a multilayer stack and forming an opening in a fin as an initial step in forming a multilayer source/drain region. The opening is formed into a parasitic channel region of the fin. Once the opening has been formed, a source/drain barrier material is deposited using a bottom-up deposition process at the bottom of the opening to a level below the multilayer stack. A multilayer source/drain region is formed over the source/drain barrier material. A stack of nanostructures is formed by removing sacrificial layers of the multilayer stack, the multilayer source/drain region being electrically coupled to the stack of nanostructures.

Semiconductor devices and methods of fabrication are described herein. The method includes steps for patterning fins in a multilayer stack and forming an opening in a fin and into a substrate as an initial step in forming a source/drain region. A first semiconductor material is epitaxially grown from channels exposed along sidewalls of the opening to form first source/drain structures. A second semiconductor material is epitaxially grown from the first semiconductor material to form a second source/drain structure over and to fill a space between the first source/drain structures. A bottom of the second source/drain structure is located below a bottommost surface of the first source/drain structures. The second semiconductor material has a greater concentration percentage by volume of germanium than the first semiconductor material. A stack of nanostructures is formed by removing sacrificial layers of the multilayer stack, the second semiconductor material being electrically coupled to the nanostructures.