Preparation Of Ti/Nb Amorphous Oxide Films And Research Of Their Memory Properties

At present,due to the limitations of the physical theory and the critical size of induced preparation technology,traditional flash memory is difficult to meet the needs of today's information technology for ultra-fast and high-density storage.A variety of new types of memory devices have been proposed,such as ferroelectric memory,phase transition memory,magnetic memory,phase transition memory,and random resistance memory,which hava the characteristics of simple structure,low operating voltage,good durability,and multi-stage storage.Random resistance switching memory is considered to be one of the most potential storage technologies to replace traditional storage technologies.It has been found that many materials have memory resistance,and mechanism of memory resistance of these materials has not yet been clarified,so there is still a lot of research space.The amorphous network structure of amorphous semiconductor provides a large amount of surface and defect states.And amorphous semiconductor is easy to prepare and is suitable for research as a dielectric material to memristors.In order to study the mechanism of memory effect of the amorphous oxide film,amorphous titanium oxide and niobium oxide films were prepared by the electrochemical anodizing method.By controlling time and voltage separately,different morphology and thickness of oxide films were obtained.The I-V curve is measured with the silver as the top electrode,Ti and Nb substrate as the bottom electrode,respectively.The main findings are summarized as follows:Titanium oxide thin films are prepared by electrochemical anodized titanium foil with different time.A thin film of titanium dioxide of different thickness was obtained,and the device Ag/TiO₂?with different thickness?/Ti was prepared with silver as the top electrode to test its electrical properties.The memristor device prepared with 300 s of oxidation time has the best memory effect,the switch ratio reaches²7.8,and the switch mechanism of the memory is obtained as the space charge limit current model by further analyzing the device's double logarithm I-V curve.However,when we utilized Au as the top electrode to our device?Au/TiO₂/Ti?displays non-hysteresis.While,it is found that the device has a memory effect due to the conductive filaments formed when Ag used as top electrode,and there is a phenomenon in which the memory resistance effect and the negative differential effect coexist.The electrochemical anodized niobium oxide thin film was prepared by changing the voltage,and getting niobium oxide thin films with different colors.Also,it was found that the color of the thin film had a corresponding relationship with the thickness.The Ag/Nb₂O₅?different colors?transparent?/Nb devices are then prepared with silver as the top electrode.By testing the electrical properties of the devices,it is concluded that the memory resistance performance is best when the film color is bright yellow?thickness is⁸5 nm?,and it can cycle stable for 100 laps.The switching ratio also reached 10²,and the large switch ratio was mainly due to the presence of the Schottky barrier at the interface.Further analysis of the double logarithm I-V curve shows that the resistance switching mechanism of the memristor is the space-charge-limited current?low pressure?and the Schottky emission?high pressure?model.When the thickness of Nb₂O₅ is less than 85 nm,the conductive motor is changed,and the current conduction of the memristor follows ohmic conduction.