US Patent 7446393 Co-sputter deposition of metal-doped chalcogenides

The present invention is related to methods and apparatus that allow a chalcogenide glass such as germanium selenide (GexSe1-x) to be doped with a metal such as silver, copper, or zinc without utilizing an ultraviolet (UV) photodoping step to dope the chalcogenide glass with the metal. The chalcogenide glass doped with the metal can be used to store data in a memory device. Advantageously, the systems and methods co-sputter the metal and the chalcogenide glass and allow for relatively precise and efficient control of a constituent ratio between the doping metal and the chalcogenide glass. Further advantageously, the systems and methods enable the doping of the chalcogenide glass with a relatively high degree of uniformity over the depth of the formed layer of chalcogenide glass and the metal. Also, the systems and methods allow a metal concentration to be varied in a controlled manner along the thin film depth.