Investigation of random telegraph noise amplitudes in hafnium oxide resistive memory devices

Abstract

Statistical characterization of two-level random telegraph noise (RTN) amplitude distribution in a hafnium oxide resistive memory has been performed. We find that two-level RTN in HRS exhibits a large amplitude distribution tail, as compared to LRS. To investigate an RTN trap position in a hafnium oxide film, we measure the dependence of electron capture and emission times of RTN on applied read voltage. A correlation between an RTN trap position and RTN amplitude is found. A quasi-two-dimensional RTN amplitude simulation based on trap-assisted electron sequential tunneling is developed. Our study shows that RTN traps in a rupture region of a hafnium oxide film are responsible for an RTN large-amplitude tail in HRS mostly.

Probing the Critical Region of Conductive Filament in Nanoscale HfO2 Resistive-Switching Device by Random Telegraph Signals

“…7 compares the measured RTS amplitude distributions at HRS, weak LRS and LRS. The distribution becomes wider at higher resistance, and a significant tail is observed at large RTS amplitude, as compared to LRS, agreeing with previous results [26]. The large RTS amplitude at HRS suggests that the trapping/ detrapping into/from the defects within CFR may lead to large noise during device read operations.…”

Optimization of Random Telegraph Noise Characteristics in Memristor for True Random Number Generator

“…This is because the effective trap energy can be modulated depending on the bias conditions and reduced with a higher read voltage considering the downward band bending near the TE. [ 64,65 ] The reduced effective trap energy by the applied voltage increases the capture probability of electrons in the trap, reducing the capture time probability as a result. Figure 4b shows the statistical distributions of effective trap energy at the read voltage of 0.08 V according to the conductance state.…”

Investigation of Preexisting and Generated Defects in Nonfilamentary a-Si/TiO2 RRAM and Their Impacts on RTN Amplitude Distribution

“…3&4 [3]. Defect's location is extracted from the dependence of RTN's mean time constants on bias V TE , based on the method adopted from refs [3,4,[25][26][27]. Defects can be found in both TiO 2 and a-Si.…”

“…[2,7], supporting that the conduction and switching mechanisms in filamentary and non-filamentary RRAMs are different. In filamentary RRAM, conduction at LRS is metallic-like, with electrons hopping through a filament formed by oxygen vacancies, leading to very small variability and RTN signals [4]. At HRS, its resistance is controlled by the critical constriction region where the least number of defects exist.…”

“…esistive switching memory devices have attracted numerous attentions in the past decade and are considered as a strong candidate for next generations emerging memory technology [1][2][3][4][5][6][7][8][9][10]. There are mainly two types of transition-metaloxide (TMO) based resistive switching devices (RRAM), the filamentary ones that can be made from a number of different materials, for example, HfO 2 [5], TaO x [8], TiO 2 [9], etc.…”