【摘要】 采用磁控溅射方法沉积TiO2薄膜及电极层,制备W/TiO2/ITO薄膜阻变存储器单元。利用原子力显微镜、X射线衍射仪、X射线光电子能谱仪对薄膜进行表征,测试结果表明:TiO2薄膜表面平整、致密;组织结构以非晶为主,仅有少量的金红石相TiO2(110)面结晶;钛氧比为1∶1.92,其内部存在少量的氧空位。在电学测试中,元件呈现出了稳定的双极阻变现象,V Set分布在0.92 V左右,V Reset分布在-0.82 V左右;元件窗口值稳定,数据保持特性良好。通过对元件I-V曲线线性拟合结果的分析,我们认为元件的阻变机理由导电细丝机制主导。进一步的分析发现,该导电细丝是由钨原子构成,钨原子在电场作用下发生氧化还原反应并在TiO2薄膜层中迁移,造成了导电细丝的形成和断裂。更多还原

【Abstract】 W/TiO 2/ITO thin film resistive random access memory,including TiO 2 film and electrode layers was prepared by magnetron sputtering method.The film was characterized by atomic force microscopy,X-ray diffraction,X-ray photoelectron spectroscopy.The testing results show that the surface morphology of deposited TiO 2 thin film is smooth and dense; the structure of the film is mainly amorphous phase with a small amount of crystallized rutile(110) planes; the ratio of titanium and oxygen is 1∶ 1.92 and few oxygen vacancies exist inside the film.The device displays a stable bipolar resistive switching behavior in electrical testing with V Set around 0.92 V and V Reset around-0.82 V.The stable memory window and fine retention performance are also found in electrical testing.By analyzing the linear fitting for I-V curve,it is believed that the resistive switching is governed by conducting filament.Further study showed that the conducting filament is formed by Tungsten atoms,i.e.,the redox reaction and the migration of Tungsten atoms in TiO 2 film under a bias cause the formation and rupture of conducting filaments.更多还原