Radiation Hardened Graphene based Nonvolatile Memory for Space Applications

ABSTRACT: This Air Force Phase I SBIR program would develop and demonstrate radiation hardened graphene based nonvolatile memory(NVM) for space applications. Specifically, we would combine advances in resistive memory materials, including graphene and graphene oxides, with the careful manipulation of metal ion, oxygen vacancy or other charge transport in graphene based materials, to realize the radiation hardened NVM devices and arrays with high reliability and high density. NanoSonic has demonstrated a Ta2O5 based resistive memory with on-off ratios of 10^5, device power consumption of 10^-5 Watts and switching speeds of 100ns. We have also demonstrated a successful total ionizing dose (TID) test for the nonvolatile memory under the gamma ray dose level up to 1 Mrad. The devices maintain memory functionalities with high reliability during and after the radiation exposure. During the program, we will investigate the responsible mechanisms for graghene based NVMs, including the NEM effect and ionic effect, and their resistance to radiation. We will fabricate arrayed devices with ultradense crossbar latches structure, using radiation hardened graphene to evaluate the materials and device performance. Memory device parameters namely onoff ratio, on-state current, switching time, retention time, cycling endurance, power consumption and rectification will be evaluated during Phase I using extensive facilities available in NanoSonic and Virginia Tech. Radiation testing include total ionization dose and single event effects, which will be performed at Aeroflex-RAD"s Co60 irradiator facility and Texas A & M"s Cyclotron facility. BENEFIT: The proposed radiation hardened graphene based resistive memory is critical for electronics in space. They can be fashioned into non-volatile memory, which would allow greater data density than hard drives with access times potentially similar to DRAM (Dynamic Random Access Memory). A broad band of applications of the proposed devices also include analog circuits, neuromorphic computing, programmable logic and signal processing. NanoSonic's research in the nanobridge based resistive device field has shown promise in producing NVM devices of low power consumption, high density and high performance.