Fin field effect transistors (finfet) device including a plurality of recessed regions alternating with unrecessed regions in channel stack

Abstract

A device includes a first channel structure, a second channel structure, and a gate structure. The first channel structure connects a first source region and a first drain region, and includes alternating stacking first semiconductor layers and second semiconductor layers. The second semiconductor layers have a width smaller than a width of the first semiconductor layers. The second channel structure connects a second source region and a second drain region. The second channel structure includes alternating stacking third semiconductor layers and fourth semiconductor layers. The fourth semiconductor layers have a width smaller than a width of the third semiconductor layers. The gate structure wraps around the first and second channel structures.