Semiconductor devices and methods of manufacturing thereof

A semiconductor device, comprising:

• a first stack structure comprising a first plurality of channel layers vertically spaced from one another, wherein the first plurality of channel layers extend along a first direction;
• a second stack structure comprising a second plurality of channel layers vertically spaced from one another, wherein the second plurality of channel layers also extend along the first direction;
• an isolation structure that is disposed between the first and second stack structures along the a second direction perpendicular to the first direction and embeds respective lower portions of the first and second stack structures;
• and
• a first gate structure that extends along the second direction, wherein the first gate structure comprises a first portion that wraps around each of the first plurality of channel layers and a second portion that wraps around each of the second plurality of channel layers;
• wherein the first gate structure further comprises a third portion that connects the first and second portions to each other and contacts a top surface of the isolation structure.

A method for making a semiconductor device, comprising:

• forming a first fin structure and a second fin structure over a substrate, wherein the first and second fin structures both extend along a first direction, and wherein each of the first and second fin structures comprises a plurality of channel layers and a plurality of sacrificial layers vertically interleave with each other;
• depositing a cladding layer over first and second fin structures, wherein the cladding layer comprises at least one semiconductor material;
• and
• etching the cladding layer, while remaining a portion of the cladding layer that laterally extends between the first and second fin structures.