A stable undoped low-voltage memristor cell based on Titania (TiOx)

Abstract

An asymmetric memristive device fabricated with a titania (TiO _x )-based switching layer deposited through atomic layer deposition with a thickness of ∼37 nm was investigated. X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy coupled with energy-dispersive x-ray spectroscopy were employed for device structural characterization. A unipolar resistive switching behavior (both at positive and negative voltages) was observed through the memristor’s current–voltage characteristics. A remarkably smaller forming voltage (from the top Pt electrode to the grounded Au electrode) of 0.46 V was achieved, while it approached (positive bias from the Au electrode and holding Pt electrode as grounded) 0.25 V, which is a much smaller forming voltage than has ever been reported for titanium-based oxides without doping. The retention and endurance characterization over 2000 switching cycles were satisfactory without degradation.

Keywords

• low forming voltage
• unipolar switching
• memristor
• resistive switching
• asymmetric memristor structure