Study On The Performance Optimization And Physical Mechanism Of NbO_x Selector

In recent years,with the development of emerging technologies,such as artificial intelligence and cloud computing,the requirements for information storage increase gradually.In order to improve the density of memory,the size of device is constantly reducing and 3D memory has become the research hotspots.Memory can be easily integrated in crossbar arrays to achieve the highest integration density in theory,so it becomes the preferred method for large-scale storage integration.However,the sneak path current problem in the crossbar arrays structure will seriously affect the performance,which may cause information misreading.The selector in series of memory(one-selector one-resistor,1S1R)is considered as one of the most potential solutions to the problem.Therefore,it is vital to develop the selectors with high performance.Moreover,the selector based on metal-insulator transition(MIT)is widely concerned because of its simple composition and structure.In this study,the physical mechanisms and performance optimization of the NbO_x selector based on MIT effect were studied.By preparing and testing the Pt/NbO_x/Ti N device,the threshold switching and1S1R properties were studied.In addition,the threshold switching performance was optimized by inserting the tunneling layer.The main work is summarized as follows:First,for Pt/NbO_x/Ti N device,the effect of ambient temperature on the performance was studied,and the temperature stability was verified and analyzed.With the temperature increasing,the device had the smaller switching voltage and the less fluctuation range,indicating that it had excellent thermal stability.Meanwhile,by fitting the electrical data of the device,it was verified that the results satisfied the Schottky emission.Furthermore,combined with the law of heat conduction,the reason of the change of voltage with temperature was clarified.Second,the two different modes of 1S1R properties of Pt/NbO_x/Ti N device were investigated.The influence of ambient temperature and compliance current on the 1S1R performance was revealed.As the temperature or the compliance current increased,the probability of appearance of the different modes was different.Meanwhile,a model was built to deeply analyze the physical mechanism of multiple behaviors of the device and the finite element method was utilized to simulate,which provided further support for understanding and analyzing the degradation mechanism of the 1S1R characteristics.Finally,the threshold switching performance of Pt/NbO_x/Zr O₂/Ti N tunneling device was investigated.The tunneling device exhibited smaller threshold voltage,lower power consumption,and better stability and uniformity.Meanwhile,the experimental results were further supported by the fitting of I-V curve and thermal field analysis by using the finite element simulation analysis.Then,the influence of the thickness of the threshold switching region and the electron doping on the performance was deeply analyzed to understand the physical mechanism.