Multi-gate device and related methods

A method, comprising:

• providing a fin structure including epitaxial layers of a first composition interposed by epitaxial layers of a second composition, wherein the epitaxial layers of the first composition are at least twice as thick as the epitaxial layers of the second composition;
• forming a dummy gate over the fin structure and a spacer layer on sidewalls of the dummy gate;
• etching lateral ends of the epitaxial layers of the first composition to form recesses, the recesses disposed beneath the spacer layer and between adjacent epitaxial layers of the second composition;
• and
• forming a silicon (Si) cap layer on opposing ends of the epitaxial layers of the second composition and within the recesses.

A semiconductor device, comprising:

• a fin extending from a substrate, wherein the fin includes a plurality of semiconductor channel layers, and wherein each semiconductor channel layer of the plurality of semiconductor channel layers includes a channel region and a lightly-doped drain (LDD) region;
• a cap layer surrounding the LDD region of each semiconductor channel layer of the plurality of semiconductor channel layers;
• and
• inner spacers disposed between first portions of the cap layer disposed in the LDD region of adjacent semiconductor channel layers of the plurality of semiconductor channel layers;
• wherein a first thickness of the plurality of semiconductor channel layers in the LDD region combined with a second thickness of the cap layer provides an effective thickness of the plurality of semiconductor channel layers in the LDD region, and wherein the effective thickness is greater than a third thickness of the plurality of semiconductor channel layers in the channel region.