Solution-phase deposition and nanopatterning of GeSbSe phase-change materials

• Published in: Nature materials Vol. 6; no. 5; pp. 352 - 356
• Main Authors: Milliron, Delia J, Raoux, Simone, Shelby, Robert M, Jordan-Sweet, Jean
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.05.2007
• Subjects: Computer memory; Data storage; Heating; Information storage; Lithography; Low temperature; Materials science; Nanotechnology; Thin films
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat1887

Chalcogenide films with reversible amorphous-crystalline phase transitions have been commercialized as optically rewritable data-storage media, and intensive effort is now focused on integrating them into electrically addressed non-volatile memory devices (phase-change random-access memory or PCRAM). Although optical data storage is accomplished by laser-induced heating of continuous films, electronic memory requires integration of discrete nanoscale phase-change material features with read/write electronics. Currently, phase-change films are most commonly deposited by sputter deposition, and patterned by conventional lithography. Metal chalcogenide films for transistor applications have recently been deposited by a low-temperature, solution-phase route. Here, we extend this methodology to prepare thin films and nanostructures of GeSbSe phase-change materials. We report the ready tuneability of phase-change properties in GeSbSe films through composition variation achieved by combining novel precursors in solution. Rapid, submicrosecond phase switching is observed by laser-pulse annealing. We also demonstrate that prepatterned holes can be filled to fabricate phase-change nanostructures from hundreds down to tens of nanometres in size, offering enhanced flexibility in fabricating PCRAM devices with reduced current requirements.