Research Of TiO₂/SiO_x Based Resistive Random Access Memories And Electrical Properties Of Graphene Oxide

In order to fulfill the information storage needs of modern societies,the performance of non-volatile memories(NVMs)is being improved continuously.In the last few years,resistive random access memories(RRAM)have raised as one of the most promising technologies for future information storage due to their excellent performance and easy fabrication.In the first part,we present a novel strategy to further extend the performance of RRAMs.By using cheap and industry-friendly materials(Ti,Ti O2,Si OX,and n++Si),we develop memory cells that show both filamentary and distributed resistive switching(RS)simultaneously.The devices exhibit unprecedented hysteretic I-V characteristics,high current on/off ratios up to ~5 orders of magnitude,ultra-low currents in high resistive state and low resistive state(100 p A and 125 n A at-0.1 V,respectively),sharp switching transitions,good cycle-to-cycle endurance(>1000 cycles)and low device-to-device variability.Until now,we are not aware of any other resistive switching memories exhibiting such electrical characteristics,which may open a new door for the development of advanced NVMs combining the advantages of filamentary and distributed resistive switching mechanisms.Another interesting dielectric material for electronic devices is graphene oxide(GO).However,its reliability as dielectric has never been analyzed in depth.In the second part,dielectric breakdown in GO thin films(prepared by spin coating method)has been studied through current-voltage and current-time curves measured in both a probestation and a conductive atomic force microscope(C-AFM).We find that GO thin films show very stable and reproducible voltage breakdown.Interestingly,the breakdown voltage has no obvious relationship with the device size(? 25 ? 25 ?m2)and top electrode.In total,more than 400 devices were measured,and all of them show similar dielectric breakdown,indicating very low device to device variability.As far as we know,this would be the first work about statistical analysis of the dielectric breakdown process in GO thin films,which may accelerate application of GO in microelectronic devices.