SEMICONDUCTOR DEVICES

A semiconductor device includes first and second active fins on first and second regions of a substrate, an isolation pattern on a boundary between the first and second regions and portions of the first and second regions adjacent thereto and separating the first and second active fins, a first gate structure on the first active fin and the isolation pattern on the first region, a second gate structure on the second active fin and the isolation pattern on the second region, a first source/drain layer on the first active fin adjacent to the first gate structure, and a second source/drain layer on the second active fin adjacent to the second gate structure. A width of a portion of the first gate structure overlapping the first active fin is greater than that of a portion of the second gate structure overlapping the second active fin.