High-Frequency TaOx-Based Compact Oscillators

• Published in: IEEE transactions on electron devices Vol. 62; no. 11; pp. 3857 - 3862
• Main Authors: Sharma, Abhishek A., Yunlu Li, Skowronski, Marek, Bain, James A., Weldon, Jeffrey A.
• Format: Journal Article
• Language: English
• Published: IEEE 01.11.2015
• Subjects: compact oscillator; Electronic ballasts; filament dynamics; filament formation; forming; Frequency shift keying; high frequency; metal-insulator transition; one resistor (1T1R); One transistor; Oscillators; oscillatory neural network (ONN); oxide oscillators; Resistance; resistive random access memory (RRAM); Resistors; TaOₓ; Transistors; Voltage measurement; one resistor (1T1R); forming; metal–insulator transition; TaOx; filament dynamics; compact oscillator; high frequency; oxide oscillators; One transistor; resistive random access memory (RRAM); oscillatory neural network (ONN); filament formation
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2015.2475623

In this paper, we demonstrate three key features of oxide-based nano-oscillators: 1) the observation of threshold switching and filamentary oscillations in TaO x ; 2) the highest frequency achieved by oxide-based oscillators; and 3) a study with linear (resistor) and nonlinear (transistor) ballasts to clearly understand the role of filament dynamics in scaling. These oscillators show frequency tunability over the range of 20 kHz-250 MHz, with 250 MHz being the highest reported frequency for this class of oscillators. Different types of ballasts show frequency tunability using two distinct methods: 1) by tuning the channel resistance of the transistor and 2) by increasing the rail voltage across the ballast-device pair. This sheds new light on the oscillator dynamics for dense oscillator arrays aimed at oscillatory neural networks and other applications.