| Summary: | 碩士 === 國立臺灣科技大學 === 科技管理所 === 99 === In our research, we fabricate Cu/Cu-SiO2/TaN and TaN/Cu-SiO2/TaN devices by sputter and co-sputter. From the result of electrical analyses, both Cu/Cu-SiO2/TaN and TaN/Cu-SiO2/TaN device show resistance switching property. Device which uses TaN as both top electrode and bottom electrode shows 100 stable switching cycle, and the resistance ratio of high resistance state(HRS) to low resistance state(LRS) is about 10.
In order to improve the memory device’s stability and to avoid write/erase mistake, a TaON layer is formed by oxidation of bottom TaN electrode using oxygen plasma. The results of electrical analyses show that Cu/Cu-SiO2/TaON/TaN device can remain resistance switching after 100 switching cycle, and the resistance ratio of HRS to LRS is about 103~106. The TaN/Cu-SiO2/TaON/TaN device also shows the resistance switching property, with the resistance ratio of HRS to LRS achieving 102.
According to the result of electrical analyses, we assume that there are abundant oxygen vacancies in Cu-SiO2 thin film. Thus additional O2 were added when Cu-SiO2 to deposit thin film in order to reduce the amount of oxygen vacancies. The results of electrical analyses show that the stable switching cycle can achieve more than 500 times, and the resistance ratio of HRS to LRS is about 5x103. In order to realize the resistance switching effect caused by Cu atom and oxygen vacancy, we increase the Cu content in Cu-SiO2 thin film, and the results of electrical analyses show that device can remain stable resistance switching above 100 times, and the resistance ratio of HRS to LRS can achieve 102.
In this thesis, we show that adding TaON oxide layer and reducing concentration of oxygen vacancies can improve device operation stability. And the results of electrical analyses show that the resistance switching property is possibly related to oxygen vacancy percolation conduction path, and the electron conduction is throy electron hopping in the LRS.
|
|---|
