Multi-level Storage And Interfacial Modification Based On Oxide Resistance Memory

In recent years,with the popularity and the continuous development of portable electronic products,such as smart phones,digital cameras,tablet computer and removable storage devices,the nonvolatile memory market explosively grow.Flash memory based on charge storage concept is the mainstream products in nonvolatile memory market.However,flash memory suffers from several obvious disadvantages such as slow program speed(>10 ?s),poor endurance(<106 cycles)and high operating voltage(>10 V).Moreover,flash memory will reach their physical miniaturization limitation in the near future,it's difficult to further improve performance.Hence,developing emerging nonvolatile memory technology based new storage concept is urgent.Resistance random access memory(RRAM),based on the resistance switching(RS)storage concept,has been considered the most promising next-generation nonvolatile memory,due to simple structure,compatibility with current CMOS process,fast switching speed,easy miniaturization and 3 dimension stackable and other outstanding advantages.However,there are still some challenges with RRAM memory.For example,the resistance mechanism is not completely clear,multilevel storage is difficult to control,device parameters suffer serious variation,difficult to both optimize the reset current and data retention,etc.Regarding these issues,this paper studies the physical mechanism and performance control of RRAM,main works is as follows:(1)Regarding multilevel storage of RRAM,put forward the idea of doping metal nanoparticles into RS function layer to realize NDR effect;Pt/Ag metal nanoparticles are formed in Pt/SiO2/Pt RS function layer with ion implantation,the devices show ovonic NDR effect.By controlling RESET stop voltage,realize multilevel storage;with TEM,EDS and other physical analysis method,we illustrate the multilevel storage physical mechanism is electron tunneling transmission between the metal nanocrystals,by controlling voltage to realize band bend,adjust tunneling channel,achieve different tunneling current,realize multilevel storage.(2)Regarding RESET current of RRAM,the method of inserting two-dimensional material to adjust performance is proposed.By insert multiple layers MoS2,the Ag/ZrO2/MoS2/Pt devices are prepared.With low conductivity of MoS2,the overshoot current in SET process is suppressed,thus the RESET current is reduced by an order of magnitude;With low thermal conductivity of MoS2,the RESET process is transformed from abrupt switching to analog switching,which is beneficial to realize the bionic function of synaptic synapse.The dynamic process of filament growth is simulated by MATLAB,which proves that the internal temperature of the device is higher with inserted MoS2 during Forming,many Ag ions diffuse into the resistive function layer,lower the dielectric properties of the RS layer and voltage divide of MoS2,realize the analog switching RESET...