In one embodiment, first and second multi-layer pattern structures are formed over first and second regions of a substrate, respectively. The first and second multi-layer pattern structures include first and second support layer patterns, respectively. The first and second multi-layer pattern structures define first and second openings, respectively. The first and second openings partially expose a portion of the first region and a portion of the second region, respectively. First and second liner patterns are formed on an inner face of the first opening and an inner face of the second opening, respectively. A first etching process is performed on the first multi-layer pattern structure until the first support layer pattern is removed. A second etching process is performed to remove the second multi-layer pattern structure except for the second support layer pattern.