| Summary: | 碩士 === 長庚大學 === 光電工程研究所 === 94 === Non-volatile memory (NVM) represented as flash memory has already become an indispensable tool for modern portable and mobile electronic devices. Therefore they are quite reliant on the development of NVMs that have high speed, high unit cell density, low power consumption, high endurance, and low price. One of the candidates of next generation advanced NVMs is resistive random access memory (RRAM) that can replace flash memory. The simple structure consists of two terminal electrodes that sandwich a material normally resistive to change resistance. Applying a current or voltage pulse can, however, change the material’s resistance.
Electric-field controlled resistive memory switching phenomenon in metal oxide with metal-insulator-metal structure is possibility for non-volatile memory application. However, the switching mechanisms of RRAM are still unclear. To explain the memory switching in binary metal oxide material, various models have proposed such as filament conductions, charge trapping defects states inside the band gap, charge trap states at electrode/oxide interface and the change in the oxidation state of the cations, have been suggested.
In this thesis, the binary metal oxide for resistor layer was studied which were metal-insulator-metal structure. First, the way to probe into by paper review, the mechanism which gave rise to negative differential resistance fell into two parts: (Ⅰ) processes in which special semi- permanent space-charge distributions are set up. (Ⅱ) processes which involve a phase change or atomic rearrangement of host insulator. Further, the resistance switching behavior using voltage controlled in HfO2, TiO2 and NiO metal oxide material were reported. The metal oxide were deposited on Pt/Ti/SiO2 substrate. In the experiment, utilizing different oxygen content, various substrate temperature and change the stack structure in order to observe the resistance switching behavior successfully.
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