Formation of gate-all-around devices and structures thereof

Abstract

Methods and structures for inserting disposable interposers include forming a first gate over a first fin and a first spacer layer on sidewalls of the first gate, and a second gate over a second fin and a second spacer layer on sidewalls of the second gate. The method further includes replacing, within the first fin, epitaxial layers of a second composition with disposable interposers disposed beneath the first gate and first inner spacers on opposing ends of the disposable interposers. The method further includes etching back, within the second fin, opposing lateral ends of the epitaxial layers of the second composition to form recesses disposed beneath the second spacer layer and between adjacent epitaxial layers of the first composition. The method further includes forming second inner spacers, within the second fin, within each of the recesses on the opposing lateral ends of the epitaxial layers of the second composition.