Phase change memory devices and methods for fabricating the same

A phase change memory device, comprising:

• a semiconductor substrate;
• a first conductive semiconductor layer disposed over the semiconductor substrate, wherein the first conductive semiconductor layer has a first conductivity type;
• a first dielectric layer disposed over the semiconductor substrate, covering the first conductive semiconductor layer;
• a second conductive semiconductor layer disposed in the first dielectric layer and stacked over the first conductive semiconductor layer, wherein the second conductive semiconductor layer has a second conductivity type opposite to the first conductivity type;
• a heating electrode disposed in the first dielectric layer and formed over the second conductive semiconductor layer, wherein the heating electrode has a rectangular cross section and comprises metal silicide, and a top surface of the heating electrode is exposed by the first dielectric layer;
• a second dielectric layer disposed over the first dielectric layer, covering the heating electrode;
• a phase change material layer disposed in the second dielectric layer, covering the heating electrode;
• and
• an electrode disposed over the second dielectric layer, covering the phase change material layer.

A method for fabricating a phase change memory device, comprising:

• providing a semiconductor substrate;
• forming a first conductive semiconductor layer over the semiconductor substrate, wherein the first conductive semiconductor layer has a first conductivity type;
• forming a first dielectric layer, covering the semiconductor substrate and the first conductive semiconductor layer;
• forming a second conductive semiconductor layer and a heating electrode in the first dielectric layer, wherein the second conductive semiconductor layer and the heating electrode are sequentially stacked over the first conductive semiconductor layer, and the second conductive semiconductor layer has a second conductivity type different from the first conductivity type, and the heating electrode comprises metal silicide;
• forming a phase change material layer, covering the heating electrode and portions of the first dielectric layer adjacent to the heating electrode;
• forming a second dielectric layer, covering the first dielectric layer and the heating electrode and surrounding the phase change material layer;
• and
• forming an electrode over the second dielectric layer, covering the phase change material layer.