Open AccessImprovement of NbOx-based threshold switching devices by implementing multilayer stacks
Author(s) -
Melanie Herzig,
Martin Weiher,
Alon Ascoli,
Ronald Tetzlaff,
Thomas Mikolajick,
Stefan Slesazeck
Publication year - 2019
Publication title -
semiconductor science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.712
H-Index - 112
eISSN - 1361-6641
pISSN - 0268-1242
DOI - 10.1088/1361-6641/ab1da3
Subject(s) - neuromorphic engineering , memristor , materials science , electronic circuit , niobium oxide , threshold voltage , voltage , resistive random access memory , optoelectronics , electronic engineering , signal (programming language) , niobium , computer science , resistive touchscreen , transistor , electrical engineering , engineering , artificial neural network , machine learning , metallurgy , computer vision , programming language
In this work the I – V characteristics of a niobium oxide-based threshold switching device were optimized to match the requirements for its application in neuromorphic circuits. Those neuromorphic circuits rely on coupled oscillators utilizing the volatile resistive switching effect of the memristor. A large voltage extension of the negative differential resistance region of the threshold switch enables enhanced signal amplification, and, furthermore, can lead to a better tolerance to device variability. A symmetric switching behavior as well as a high device stability for the operation in both voltage polarities is mandatory to allow the integration in circuits that utilize the connection of several threshold switching devices operated in different polarities. These properties are similarly important for the adoption of the threshold switches as selector devices in bipolar resistive memory arrays. Furthermore, a low forming voltage is desirable because it leads to a better control during the forming step. To meet all those requirements the application of multilayer stacks consisting of niobium and niobium oxide layers is proposed and their optimization is investigated in detail.