First Principles Research On The Electric Transport Mechanism Of HfO₂-based Memristors

With the in-depth development of information technology,the requirements in market for high density,low cost,high reliability are more and more critical.As one of the most promising candidates for the next generation non-volatile memory,it has lots of merits such as high speed,low power consumption,simple metal-insulator-metal?MIM?sandwich structure,3D integration feasible,Logical operation,complementary metal-oxide-semiconductor?CMOS?technology-compatible fabrication process.These advantages make it possible that the saving and computing of information are combined together,which is a huge breakthrough of new computer architecture.And it has a great performance in neuromorphic computing because of stable multivalued storage on memristor.The clear resistive switching mechanisms are the primary scientific issue for achieving high-performance memory and computing capabilities regulation.And these are not figure out yet.That is the reason why we are unable to make most use of memristor.Equipped with the advantages of excellent performance of resistive switching and CMOS process compatibility,HfO₂ is the material which is most likely applied in large-scale industrialization beyond so many memoristor materials.And it is known to us that the most popular interpretation to mechanism of resistive switching is conductive filamentary.In this paper,first principle method is employed to investigate different filamentary HfOx based memristor models and electric transportation.So these results are able to guide the preparation and capabilities regulation of memristor.In this work density functional theory coupled with non-equilibrium green functional is employed to study the transmission spectra and volt ampere characteristic curve of a Pt/HfOx/Pt memristor cell,either pristine or with various conductive filament compositions.GGA-1/2 method is proposed,which providing band gaps agreed well with experimental data,to obtain accurate Schottky barrier and current under certain bias of Pt/HfOx/Pt model.In this paper,we calculated the Hf₃O/HfO₂ and Hf₂O/HfO₂ interface models.Then the influence of different oxygen content on the barrier height is also discussed.The deep research in these electric transport models will provide solid theoretical basis for preparation of high-performance memristor.