Semiconductor device including an internal spacer

Abstract

A semiconductor device includes a substrate, first to sixth nanowires extending in a first direction and spaced apart from each other, first to third gate electrodes extending in a second direction and respectively on first to third regions of the substrate, a first interface layer of a first thickness between the first gate electrode and the second nanowire, a second interface layer of a second thickness between the third gate electrode and the sixth nanowire. The first to third gate electrodes respectively may surround the first and second nanowires, third and fourth nanowires, and fifth and sixth nanowires. A first internal spacer may be on a side wall of at least one of the first to third gate electrodes. In the first direction, a first length of the first nanowire may be smaller than a second length of the third nanowire.