Semiconductor device

Abstract

A semiconductor device may include first and second active regions on a substrate, first and second insulating structures on the first and second active regions, respectively, vertically stacked channel layers on each of the first and second insulating structures, first and second gate structures intersecting the first and second active regions, respectively, and surrounding the channel layers, first and second source/drain regions doped with different conductivity-type impurities, the first and second source/drain regions being on sides of the first and second gate structures, respectively, and contacting the channel layers, and at least a portion of each of the first and second insulating structures extending upwardly along a side surface of a corresponding one of the first and second source/drain regions.