Space charge polarization induced memory in SmNiO3/Si transistors

作者：Lee Sang Hyeon; Kim Moonkyung^*; Ha Sieu D; Lee Jo Won; Ramanathan Shriram; Tiwari Sandip

来源：Applied Physics Letters, 2013, 102(7): 072102.

DOI：10.1063/1.4790394

The correlated oxide, SmNiO3 (SNO), is characterized and explored as a phase transition material in silicon capacitors and transistors with SNO as a floating gate sandwiched between silicon dioxide gate insulators. The structures show hysteresis at low bias voltages. The capacitance and its voltage hysteresis window increase as the frequency of the applied field decreases with a response time of polarization of above a microsecond. This suggests a space charge polarization dominated by low frequency permittivity response. Instability of 3+ oxidation state of Ni and presence of oxygen vacancies are believed to lead to a polarization effect through Poole-Frenkel charge trapping/de-trapping. Metal-oxide-semiconductor transistors show counterclockwise voltage hysteresis consistent with polarization switching effect. The stored information decays gradually due to the depolarization field with retention times of the order of 10 s at room temperature.

• 出版日期2013-2-18