Semiconductor device having stepped multi-stack transistor structure

Abstract

A semiconductor device include: a substrate; a 1transistor formed above the substrate, the 1transistor including a 1channel set of a plurality of 1nanosheet layers, a 1gate structure surrounding the 1nanosheet layers, and 1and 2source/drain regions at both ends of the 1channel set; and a 2transistor formed above the 1transistor in a vertical direction, the 2transistor including a 2channel set of a plurality of 2nanosheet layers, a 2gate structure surrounding the 2nanosheet layers, and 3and 4source/drain regions at both ends of the 2channel set, wherein the 1channel set has a greater width than the 2channel set, wherein a number of the 1nanosheet layers is smaller than a number of the 2nanosheet layers, and wherein a sum of effective channel widths of the 1nanosheet layers is substantially equal to a sum of effective channel width of the 2nanosheet layers.