Effect Of Dielectric Film Defects And Electrode Materials On The Electrical Properties Of H-BN Based Memristor

Memristor is a basic electronic element for memory storage since its multiple resistive states which are switchable and maintainable under different voltages.Thanks to the small size,a simple structure,and the compatibility with large-scale integration,memristor shows a great potential in memory storing,data computing and integrating high-density circuits.Meanwhile,introducing 2D-layered-materials into microelectronic chips,which can greatly reduce the device size while guaranteeing the electrical characteristics,offers a possible solution to break the bottleneck of Moore’s Law.This work has systematically investigated and analyzed the 2D-layered-material(hBN)based memristor.First,the effect of electrode materials on the switching modes of h-BN based memristor was studied.When using Au,Ag,and Pt as biased electrodes,the h-BN based memristor shows non-volatile resistive switching(RS),volatile RS and nonRS behavior respectively.According to the relationship between the electrode materials and the RS modes,a more optimized scheme for electrodes of h-BN based memristor can be found.Secondly,the defects and flaws of h-BN films were statistically characterized,and their influence on the electrical properties of the memristor was explored.According to the effect on the local resistance of h-BN,these flaws and defects can be divided into two groups:increasing and decreasing the local resistance.Among them,the second group that reduces the local resistance has significant impacts on the electrical properties of the memristor.It mainly originates from the intrinsic defects in h-BN which generated during chemical vapor deposition.Since RS phenomenon is always driven by the most conductive location in memristors,these defects provide localized regions where dielectric breakdown is more likely to happen,and thus have influenced the RS and electrical properties of h-BN based memristors.Finally,the morphology of the h-BN and the electrical properties of device during the scale down process were investigated.The transferred h-BN film tends to produce fewer wrinkles when scaling down the device size from micron to nanoscale,and the nanoscale h-BN memristor exhibits good variability.In conclusion,this thesis aims to investigate the effects of defects,electrode materials,and device size on the electrical properties of h-BN based memristor.On the one hand,this paper uncovers that the defects have a significant impact on the electrical properties of memristors,and analyzes the effect of these defects on the dielectric breakdown in h-BN film.On the other hand,this thesis discusses the electrical properties of the device with different electrode materials and device scales,which gives guidlines for the design,selection and integration of h-BN memristors in circuits.