According to some embodiments of the present invention, there are provided PRAMS having a phase-change layer pattern interposed between a molding layer and a forming layer pattern, and methods of forming the same that include a node conductive layer pattern, a molding layer, a forming layer pattern and a protecting layer. The molding layer, the forming layer pattern and the protecting layer are formed to cover the planarized interlayer insulating layer and the node conductive layer pattern. A lower electrode is interposed between the molding layer and the planarized interlayer insulating layer. A phase-change layer pattern is formed on the planarized interlayer insulating layer. A spacer pattern is disposed between the phase-change layer pattern and the molding layer.