A device includes an insulating layer on a substrate having a lower conductive pattern, the insulating layer having a contact hole that penetrates the insulating layer and exposes a portion of the lower conductive pattern, a catalytic pattern having a first portion on the exposed portion of the lower conductive pattern and a second portion on a sidewall of the contact hole, a spacer on the sidewall of the contact hole, wherein the second portion of the catalytic pattern is disposed between the spacer and the sidewall, and a contact plug in the contact hole and contacting the catalytic pattern, the contact plug being a carbon nanotube material.