Selective area doping for Mott neuromorphic electronics

Abstract

The cointegration of artificial neuronal and synaptic devices with homotypic materials and structures can greatly simplify the fabrication of neuromorphic hardware. We demonstrate experimental realization of vanadium dioxide (VO 2 ) artificial neurons and synapses on the same substrate through selective area carrier doping. By locally configuring pairs of catalytic and inert electrodes that enable nanoscale control over carrier density, volatility or nonvolatility can be appropriately assigned to each two-terminal Mott memory device per lithographic design, and both neuron- and synapse-like devices are successfully integrated on a single chip. Feedforward excitation and inhibition neural motifs are demonstrated at hardware level, followed by simulation of network-level handwritten digit and fashion product recognition tasks with experimental characteristics. Spatially selective electron doping opens up previously unidentified avenues for integration of emerging correlated semiconductors in electronic device technologies.

Nanoelectronics Using Metal–Insulator Transition

“…In such a system, co-integration between volatile and non-volatile elements needs to be considered, and memristors based on Mott insulators appear to be reconfigurable components when the MIT properties are appropriately controlled. [217,218] Several papers have discussed the superiority of memristors based on Mott insulators. For instance, experimental evidence confirms that a two-terminal VO 2based memristor can maintain operation up to 10 10 cycles, ensuring enhanced reliability and system operation, [219] And this endurance ensures improved reliability and operation of the system.…”

“…Notably, materials like NdNiO 3 and VO 2 have recently demonstrated synaptic behavior through an electrical phase alternating effect achieved by proton doping using the catalytic spillover method modifying their orbitals. [217,265] Moreover, the physical properties of MIT materials can be effectively controlled through various hysteresis control methods, such as strain effects with substrates, substitution, and interstitial doping. [258] These characteristics present exciting research opportunities in the field of resistance change memory for the future.…”

“…There are results demonstrating the behavior of a two‐terminal synaptic device through selective etching of VO 2 on sapphire and hydrogen ion doping using a catalytic spillover method with Pd and Au electrodes in Figure a. [ 217 ] In this case, hydrogen doping was selectively conducted at low temperatures using a forming gas (5% H 2 ) annealing process, employing a pattern consisting of a catalytic Pd electrode and an inert Au electrode. The hydrogen ions occupy interstitial sites within the VO 2 lattice, forming bonds with oxygen atoms while causing minimal damage to the lattice structure (figure 15b).…”

“…Pd served as catalytic metal electrodes for hydrogen doping, while undoped devices functioned as neuron elements, providing signal transfer. a,b) Reproduced with permission [217]. Copyright 2023, American Association for the Advancement of Science.…”

Manipulating the metal-to-insulator transitions of VO2 by combining compositing and doping strategies

“…1–5 Among the existing MIT materials, vanadium dioxide (VO 2 ) undergoes the most abrupt MIT behavior near room temperature ( e.g. , 341 K), which enables promising applications, such as thermochromism, 6,7 artificial intelligence, 8 infrared camouflage 9 and correlated electronic devices. 10,11 The magnitude of the T MIT of VO 2 can be further decreased (or increased) by substituting vanadium, which has a valence state of +4, with transition metal elements with higher (or lower) valence states.…”