Thickness‐dependent electroforming behavior of ultra‐thin Ta₂O₅ resistance switching layer

Abstract

Electroforming behaviours of Ta2O5 resistance switching memory cell with a diameter of 28 nm and different thickness (0.5–2.0 nm) of Ta2O5 layer have been examined. The devices showed a constant forming electric field of 0.54 V/nm regardless of Ta2O5 thickness. The electroforming with negative bias to top TiN electrode was ascribed to electric field‐ driven migration of oxygen vacancies, originally residing near the bottom interface, toward the top electrode interface and formation of conducting filaments. The estimated electroforming energy (0.094–0.14 eV) was favourably compared with the hopping energy of electrons from the VO site to a nearby Ta site. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)

Thickness effect of ultra-thin Ta2O5 resistance switching layer in 28 nm-diameter memory cell

“…It was also found that additional 0.3 nm t TaO to the targeted value is needed for fitting the experimental data, which is in agreement with the value confirmed by TEM images. Detailed discussions on this characteristic feature of electroforming step was reported in our previous study 11 .…”

Memristors for Energy‐Efficient New Computing Paradigms

“…The scaling limits of the area (≈10 nm × 10 nm) and thickness (≈2 nm) of the memristive layer were also verified by the ALD‐grown HfO 2 switching layer . Park et al worked on the electrical characterizations of electro‐forming and resistive switching in 0.8‐, 1.3‐, 1.8‐, and 2.3‐nm‐thick ALD‐grown Ta 2 O 5 switching layers formed on a 28‐nm‐diameter contact plug . It was notable that a Ta 2 O 5 switching layer as thin as 0.8 nm showed fluent resistance switching performance, thus demonstrating the extreme scalability of the material.…”

Impact of the Atomic Layer-Deposited Ru Electrode Surface Morphology on Resistive Switching Properties of TaOx-Based Memory Structures

“…In this work, therefore, the RS behaviors of Ru/TaO x /Ta RRAM structures, where Ru serves as the inert BE and TaO x and Ta are the RS layer and top electrode (TE), respectively, are carefully examined. In this case, the chemically active Ta TE induced oxygen vacancies in the TaO x layer, making it a viable RS layer . The focus of this work is placed on the influence of the roughness of the Ru BE film deposited on the TiN layer, which was controlled by changing the cycle number of the ALD process, on the RRAM performance of the TaO x layer.…”

“…In this case, the chemically active Ta TE induced oxygen vacancies in the TaO x layer, making it a viable RS layer. 31 The focus of this work is placed on the influence of the roughness of the Ru BE film deposited on the TiN layer, which was controlled by changing the cycle number of the ALD process, on the RRAM performance of the TaO x layer. In contrast to the cases of capacitive devices, where the smooth Ru film generally resulted in better performance, the Ru film with a higher roughness produced superior switching uniformity and endurance in these specific RRAM cases.…”