A semiconductor device includes a first transistor pair formed over a substrate. The first transistor pair includes a n-type transistor and a p-type transistor that are stacked over one another. The n-type transistor has a first channel region that includes one or more first nano-channels with a first bandgap value. The one or more first nano-channels extend laterally along the substrate, are stacked over the substrate and spaced apart from one another. The p-type transistor has a second channel region that includes one or more second nano-channels made of a compound material having a second bandgap value based on a predetermined material ratio of the compound material. The one or more second nano-channels extend laterally along the substrate, are stacked over the substrate and spaced apart from one another.