Abstract: An integrated circuit device includes a pair of fin-type active regions, which extend in a first horizontal direction on a substrate, and a fin isolation insulator between ones of the pair of fin-type active regions to extend in a second horizontal direction that intersects with the first horizontal direction. The fin isolation insulator includes a first nitrogen-rich barrier film having at least one protrusion at a position that is higher than respective top surfaces of each of the pair of fin-type active regions with respect to the substrate, and a second nitrogen-rich barrier film, which is spaced apart from the first nitrogen-rich barrier film and is in a space defined by the first nitrogen-rich barrier film.

Abstract: A semiconductor device includes channels spaced apart from each other on a substrate in a vertical direction substantially perpendicular to an upper surface of the substrate, a gate structure on the substrate and bordering lower and upper surfaces and a first sidewall of at least a portion of each of the channels, and a source/drain layer on a portion of the substrate adjacent to the gate structure and contacting second sidewalls of the channels. A nitrogen-containing portion is formed at an upper portion of an uppermost one of the channels, and may be doped with nitrogen.