Integrated circuit devices

Abstract

An integrated circuit device includes: a semiconductor on insulator (SOI) substrate layer including a base substrate layer, an insulating substrate layer, and a cover substrate layer; a semiconductor substrate layer; a plurality of first fin-type active areas and a plurality of second fin-type active areas each defined by a plurality of trenches, and extending in a first horizontal direction, in above the SOI substrate layer and the semiconductor substrate layer, respectively; a plurality of nanosheet stacked structures comprising nanosheets extending in parallel with each other and spaced apart from upper surfaces of the plurality of first fin-type active areas and the plurality of second fin-type active areas; a plurality of first source/drain regions extending into the SOI substrate layer; and a plurality of second source/drain regions extending into the semiconductor substrate layer. Lower surfaces of the first and second source/drain regions may not be coplanar with each other.