Methods of forming holes using mask pattern structures

In a method of forming holes, a plurality of guide patterns physically spaced apart from each other is formed on an object layer. The guide pattern has a ring shape and includes a first opening therein. A self-aligned layer is formed on the object layer and the guide patterns to fill the first opening. Preliminary holes are formed by removing portions of the self-aligned layer which are self-assembled in the first opening and between the guide patterns neighboring each other. The object layer is partially etched through the preliminary holes.