Abstract
In this work we investigate the conductance quantization (QC or CQ)
phenomenon in the Cu/Ta2O5/Pt resistive random access memory (RRAM)
devices. The Ta2O5 film was deposited on Pt-Si substrate using RF
magnetron sputtering, followed by patterning of Cu top electrodes. The
devices demonstrate robust bipolar resistive switching behavior, with
low set and reset voltages (< 1V), and high resistance
contrast (~103 ), owing to the electrochemical
metallization mechanism. Quantized conduction was observed during the
reset operation with well-defined conduction steps. Conductance (G)
histograms revealed Gaussian distribution of G/G0 around the integral
and half-integral values, where G0 is the fundamental unit of
conductance (77.6 μS). The maximum conductance state observed was 310G0.
Moreover, the currentvoltage curves of QC reset cycles clearly revealed
that multiple conduction states appear at the same current value which
opens potential avenues for developing multi-state memory devices based
on QC states. The findings in this work contribute to the understanding
of quantized conduction in RRAM devices for non-conventional computing
applications such as in-memory and neuromorphic computation.