Abstract: A method of fabricating a semiconductor device, can be provided by forming first and second gate patterns on a semiconductor substrate. First and second insulating spacers can be formed on first and second sidewalls of the first and second gate patterns, respectively. A capping insulation can be formed on an entire surface of the semiconductor substrate including on the first and second insulating spacers. The first insulating spacers can be removed to form an air gap between the first and second gate patterns. Related devices are also disclosed.