US Patent 7723713 Layered resistance variable memory device and method of fabrication

The invention is related to methods and apparatus for providing a resistance variable memory element with improved data retention and switching characteristics. According to one embodiment of the invention, a resistance variable memory element is provided having at least one silver-selenide layer in between two glass layers, wherein at least one of the glass layers is a chalcogenide glass, preferably having a GexSe100-x composition. According to another embodiment of the invention, a resistance variable memory element is provided having at least one silver-selenide layer in between chalcogenide glass layers and further having a silver layer above at least one of said chalcogenide glass layers and a conductive adhesion layer above said silver layer. According to the another embodiment of the invention, a resistance variable memory element is provided having a first chalcogenide glass layer, a silver layer over said chalcogenide glass layer, a second chalcogenide glass layer over said silver layer, a second silver layer over said second chalcogenide glass layer, and a conductive adhesion layer over said a second silver layer.