ABSTRACTIn this work we explore the mechanisms responsible for Random Telegraph Noise
(RTN) fluctuations in HfOx Resistive Random Access Memory (RRAM)
devices. The statistical properties of the RTN are analyzed in many operating
conditions exploiting the Factorial Hidden Markov Model (FHMM) to decompose the
multilevel RTN traces in a superposition of two-level fluctuations. This allows
the simultaneous characterization of individual defects contributing to the RTN.
Results, together with multi-scale physics-based simulations, allows thoroughly
investigating the physical mechanisms which could be responsible for the RTN
current fluctuations in the two resistive states of these devices, including
also the charge transport features in a comprehensive framework. We consider two
possible options, which are the Coulomb blockade effect and the possible
existence of metastable states for the defects assisting charge transport.
Results indicate that both options may be responsible for RTN current
fluctuations in HRS, while RTN in LRS is attributed to the temporary screening
effect of the charge trapped at defect sites around the conductive filament.
Modeling of electron conduction in contact resistive random access memory devices as random telegraph noise
