US Patent 11177215 Integrated circuit device

An integrated circuit device includes a conductive line formed on a substrate, an insulating spacer covering side walls of the conductive line and extending parallel with the conductive line, and a conductive plug that is spaced apart from the conductive line with the insulating spacer therebetween. The insulating spacer includes an insulating liner contacting the conductive line, an outer spacer contacting the conductive plug, and a barrier layer between the insulating liner and the outer spacer to prevent oxygen atoms from diffusing into the outer spacer.