The Interaction of SiO_x-Based Resistive RAM Devices with Oxygen: Observations on Release and Absorption

Novel storage technologies have emerged due to typical non-volatile memory approaching its scalability limit. A candidate under development is intrinsic filamentary oxide based Resistive RAM (ReRAM), which offers appealing scalability, standard process compatibility, data retention and power consumption. Device endurance remains an issue to be tackled before commercialization. To address this, we studied our TiN/SiOx/TiN (x<2) intrinsic switching devices, which belong to a family that develops unfavorable insulating “stains” on the top electrode during high-stress operation. We provide positive correlation of these stains with the release and incorporation of oxygen exchanging with the atmosphere. During high vacuum in situ operation, we detected O2 and O2 - emission through Secondary Ion Mass Spectroscopy (SIMS) and Residual Gas Analyzer (RGA) analyses. Following cycling in a labeled oxygen environment, we detected atmospheric oxygen incorporation through ToF-SIMS depth profiling, shedding light on how filamentation may occur. We also observed significantly altered electrical behavior in high vacuum, oxygen rich and nitrogen rich atmospheres. These findings provide evidence to improve endurance of future device through the use of oxygen sinks and sources.