Synaptic transistors with aluminum oxide dielectrics enabling full audio frequency range signal processing

Sami Bolat,Jordi Sastre,Ayodhya N Tiwari,Dominik Bachmann,Antonio Cabas Vidani,Galo Torres Sevilla,Ivan Shorubalko,Evgeniia Gilshtein,Danick Briand,Alessio Mancinelli,Yaroslav E Romanyuk

doi:10.1038/s41598-020-73705-w

Abstract

The rapid evolution of the neuromorphic computing stimulates the search for novel brain-inspired electronic devices. Synaptic transistors are three-terminal devices that can mimic the chemical synapses while consuming low power, whereby an insulating dielectric layer physically separates output and input signals from each other. Appropriate choice of the dielectric is crucial in achieving a wide range of operation frequencies in these devices. Here we report synaptic transistors with printed aluminum oxide dielectrics, improving the operation frequency of solution-processed synaptic transistors by almost two orders of magnitude to 50 kHz. Fabricated devices, yielding synaptic response for all audio frequencies (20 Hz to 20 kHz), are employed in an acoustic response system to show the potential for future research in neuro-acoustic signal processing with printed oxide electronics.

Highlights

The rapid evolution of the neuromorphic computing stimulates the search for novel brain-inspired electronic devices
If the synaptic operation is enabled for a wide range of operation frequencies, metal oxide dielectrics can fill the gap between the electrolyte gated synaptic devices and ferroelectric transistors in future applications of bio-inspired electronics
We demonstrate the applicability of the synaptic transistors with printed aluminum oxide dielectrics for the acoustic signal processing in the full audio frequency range

Summary

Introduction

The rapid evolution of the neuromorphic computing stimulates the search for novel brain-inspired electronic devices. It includes several steps such as capping with titanium nitride layers and annealing at temperature levels over 450 °C to obtain the desired ferroelectric phase and requires complex lithographic patterning in order not to deteriorate the ferroelectric behavior of the insulator[10,17] Different gating mechanisms should be investigated to achieve synaptic operations in transistors without complex manufacturing to provide a wide range of operating frequencies Recently, another class of dielectrics, metal oxides, has gained the attraction of the researchers for their implementation in synaptic transistors. Synaptic transistors with printed dielectrics have only been implemented with electrolyte-gated mechanisms operating at frequencies up to 50 H z7,19

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Conclusion