Memristive behavior in BaTiO3/La0.7Sr0.3MnO3 heterostructures integrated with semiconductors

Abstract

Ferroelectric materials such as BaTiO 3 have been studied for emerging non-volatile memory applications. However, most of the previous work has been focused on this material when it was deposited on insulting oxide substrates such as SrTiO 3 . Unfortunately, this substrate is not suitable for CMOS-based microelectronics applications. This motivated us to carry out the present work. We have studied the resistive switching behavior in BaTiO 3 /La 0.7 Sr 0.3 MnO 3 (BTO/LSMO) heterostructures integrated with semiconducting substrates Si (100) using MgO/TiN buffer layers by pulsed laser deposition. Current-Voltage (I-V) measurements were conducted on BTO (500nm)/LSMO (25nm) devices at 200K. We have observed a broad hysteresis in forward and reverse voltage sweeps which is an important property for memory applications. Secondly, the R ON /R OFF ratio is estimated at ~ 150, consistent with the reported numbers (30-100) in the literature. Thirdly, the device is stable at least up to 50 cycles. However, we found that hysteretic behavior was suppressed upon oxygen annealing of the device at 1 atmospheric pressure, 200 o C for 1hr, inferring the important role of oxygen vacancies in the resistive switching behavior of BTO/LSMO device. Future work will focus on investigating the correlation between ferroelectricity and resistive switching in these devices using local probe technique piezo force microscopy (PFM) technique.