US Patent 7223627 Memory element and its method of formation

A method for controlling silver doping of a chalcogenide glass in a resistance variable memory element is disclosed herein. The method includes forming a thin metal containing layer having a thickness of less than about 250 Angstroms over a second chalcogenide glass layer, formed over a first metal containing layer, formed over a first chalcogenide glass layer. The thin metal containing layer preferably is a silver layer. An electrode may be formed over the thin silver layer. The electrode preferably does not contain silver.