US Patent 9412816 Semiconductor device including multiple nanowire transistor

A semiconductor device comprises at least two nanowire patterns over a substrate, wherein the at least two nanowire patterns have increasingly narrower widths as they extend away from the substrate and have different channel impurity concentrations. A gate electrode surrounds at least a part of the at least two nanowire patterns. A gate dielectric film is disposed between the at least two nanowire patterns and the gate electrode.