A semiconductor device is provided that includes an n-type field effect transistor including a plurality of vertically stacked silicon-containing nanowires located in one region of a semiconductor substrate, and a p-type field effect transistor including a plurality of vertically stacked silicon germanium alloy nanowires located in another region of a semiconductor substrate. Each vertically stacked silicon-containing nanowire of the n-type field effect transistor has a different shape than the shape of each vertically stacked silicon germanium alloy nanowire of the p-type field effect transistor.