US Patent 7936593 Reducing drift in chalcogenide devices

Chalcogenide materials conventionally used in chalcogenide memory devices and ovonic threshold switches may exhibit a tendency called drift, wherein threshold voltage or resistance changes with time. By providing a compensating material which exhibits an opposing tendency, the drift may be compensated. The compensating material may be mixed into a chalcogenide, may be layered with chalcogenide, may be provided with a heater, or may be provided as part of an electrode in some embodiments. Both chalcogenide and non-chalcogenide compensating materials may be used.