Bipolar resistive switching properties of TiO2-based metal/insulator/semiconductor film device
G.H. Liu1*, Y.M. Hu1, T.C. Han1
1Applied of physics, National University of Kaohsiung, Kaohsiung, Taiwan
* presenting author:GUAN-HONG LIU, email:evidence79@hotmail.com
In recent years, nonvolatile resistive random access memory (RRAM) has attracted extensive scientific and commercial interest for its simple fabrication, excellent scalability, low cost, low power consumption, high operation speed, and high storage density. So far, most studies of the RRAM devices are focused on a metal/insulator/metal configuration. In this work, we investigated the resistive switching properties of Au/TiO₂/n-type Si (metal/insulator/semiconductor, MIS) film device. A 20-nm thin TiO₂ film was deposited by using a magnetron sputtering method onto n-type conducting Si substrate. From I-V measurements, we observed a forming-free bipolar resistive switching phenomenon with the high/low resistance ratio of about 10³. The set and reset voltages are 1.4 and 0.6 eV, respectively. By performing the fitting analyses and examining the temperature dependence of the current density versus electric field curve, we deduced that the possible transport mechanism for the TiO₂-based MIS film device in high resistance state (HRS) are Schottky emission and space-charge-limited conduction, while that for the film device in low resistance state (LRS) is semiconductor-like Ohmic conduction. X-ray photoemission spectroscopy results showed that the binding energy of Ti 2p3/2 for the film device in LRS is slightly smaller than that in HRS. According to these results, we confirm that oxygen vacancies residing within TiO₂ and in the metal/insulator interface are responsible for the bipolar resistive switching of the TiO₂-based MIS film device.


Keywords: Tio2, MIS, Resistive switching