INTEGRATED CIRCUIT DEVICES INCLUDING A MULTI-LAYER STRUCTURE WITH A CONTACT EXTENDING THERETHROUGH AND METHODS OF FORMING THE SAME

摘要

Integrated circuit devices have a first substrate layer and a first transistor on the first substrate layer. A first interlayer insulating film covers the first transistor. A second substrate layer is on the first interlayer insulating film and a second transistor is on the second substrate layer. A second interlayer insulating film covers the second transistor. A contact extends through the second interlayer insulating film, the second substrate layer and the first interlayer insulating film. The contact includes a lower contact and an upper contact that contacts an upper surface of the lower contact to define an interface therebetween. The interface is located at a height no greater than a height of a top surface of the second substrate and greater than a height of a bottom surface of the second substrate layer.