Patent attributes
Disclosed are a phase change RAM device and a method for fabricating a phase change RAM device, which can efficiently lower intensity of current required for changing a phase of a phase change layer. The method includes the steps of providing a semiconductor substrate formed with an insulating interlayer including a tungsten plug, forming a first oxide layer on the semiconductor substrate, forming a pad-type bottom electrode, which makes contact with the tungsten plug, in the first oxide layer, forming a second oxide layer on the first oxide layer including the bottom electrode, and forming a porous polystyrene pattern on the second oxide layer such that a predetermined portion of the second oxide layer corresponding to a center portion of the bottom electrode is covered with the porous polystyrene pattern.