Paper EM-WeM1
Tantalum Oxide Resistive Memory Devices by IAD

Wednesday, October 21, 2015, 8:00 am, Room 210E

Resistive random access memory (ReRAM), or memristors, may be capable of significantly improving the efficiency of neuromorphic computing, when used as a central component of an analog hardware accelerator. However, the current fabrication methods for these nano-ionic resistive memory devices suffer from significant electrical variation within a single device and between devices. This variation degrades the maximum efficiency and accuracy, which can be achieved by a ReRAM-based neuromorphic accelerator.

The switchable resistive thin film at the heart of these memristor devices has been fabricated from sub-stoichiometric tantalum pentoxide using Ion Assisted Deposition (IAD). These devices fabricated with IAD have shown a significant improvement in yield and a big reduction in device performance variability. This success has been repeated many times now. The devices are fabricated from a sub-stoichiometric tantalum pentoxide using IAD to control the oxygen to tantalum ratio. The IAD deposition approach involves e-beam evaporation of tantalum metal with a reactive beam of oxygen and argon ions impinging upon the growing film. Using this technique, the oxide formation occurs at the substrate resulting in good control over film stoichiometry. IAD is a popular technique for the deposition of oxide thin films in the optical coating industry, but has now been demonstrated as a valuable method for growth of oxide electronics. The electrical and optical characterization of these films will be presented.

Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.