Patent attributes
A semiconductor structure is provided. The semiconductor structure includes a substrate, a first superlattice structure and a second superlattice structure over the substrate, a gate stack that surrounds a channel region of each of the first superlattice structures and the second superlattice structure, and source/drain structures on opposite sides of the gate stack contacting sidewalls of the first superlattice structure and the second superlattice structure. The second superlattice structure is disposed over the first superlattice structure. Each of the first superlattice structures and the second superlattice structure includes vertically stacked alternating first nanosheets of a first semiconductor material and second nanosheets of a second semiconductor material that is different from the first semiconductor material.