Array Fabrication Of The Titania-based Nano Memory And Mechnism Analysis

Recently, the Flash memory of capacitor charge type is occupying the major market share in Non-Volatile Memory ( NVM ) . With the development of microelectronics technology, size of memory cell is becoming smaller and smaller, and the integration of the storage array is still rising. When the size of Flash memory cell is reduced to nano-scale, the capability is dramatically reduced and power consumption is rising sharply. Therefore, much more superior performance of NVM is in dire need of. Currently, as a storage medium, binary metal oxides in storage technology has a simple structure, low power, and more compatibility with CMOS technology etc., and this is becoming a research hotspot.Among the binary metal oxides, the resistance switching characteristic in titania is application to resistive random access memory (RRAM) devices, and it become the next generation of non-volatile memory technology. The resistance switching characteristic has been divided into two categories: bipolar and unipolar, both of these characteristics have high resistance state and low resistance states. However, the dominant parameter that governs the physical mechanism of resistance switching of TiO2 films is still unknown. In this paper, 16×16 crossbar has been prepared to study the electrical characteristics and the physical mechanism of TiO2-based resistive switching, the principal studies are as follows:(1) Based on introducing the basic physical phenomena of electrical conductivity properties and the basic laws of nano-processing, after preparation of a 16×16 nano-memory arrays, then discussion and analysis effect from preparation process parameters of the device to the electrical properties of devices;(2) Based on preparation and testing the TiO2 resistance switching. Studying the relationship of physical parameters and bistable properties of resistance switching devices. Exploring the influence of switching characteristics by the external environment in preparation. Which physical parameters include: metal electrode material, the effective cross-sectional area, TiO2 functional layer and the thickness of TiO2 layer, oxygen vacancy concentration and distribution; Device bistable features include: switch resistance ratio, positive and negative threshold voltage, repetitive endurance, the working current, switching speed and breakdown current.(3) By introducing the basic principles and physical mechanism model of the bistable resistance switching characteristics. Analyzing and discussing the electrical properties of bistable, and based on the formation of oxygen vacancy conduction channel. Analysis of the formation process of conductive channels and the bistable memory characteristics of switching unit is applied. Establishment of high-impedance state electrical model and analysis of the physical effects of negative resistance to calculate the thickness of an effective switch.