IGZO/Al2O3 based depressed synaptic transistor

Bionic devices, such as potentiated synaptic devices, have obtained a lot of attention over the past years. However, depressed synaptic devices, which are equally significant in brain-inspired computation devices, have attracted less attention due to the lack of a proper electrolyte. In this work, an indium-gallium-zinc-oxide (IGZO) and aluminum oxide (Al2O3) film based synaptic transistor was fabricated for depressed neuromorphic applications. An Al2O3 film desposited by the atomic layer deposition (ALD) at 100 °C was used as the insulator. The low temperature introduced a lot of electron trappings at the IGZO-Al2O3 interface, which contributed to the depression feature of the synaptic transistor. The energy consumption of the fabricated transistor was estimated to be as low as ∼3.8 pJ/spike. The recovery time of a pulse was as short as ∼150 ms. Paired-pulse depression (PPD) and low-frequency filter behaviors were also mimicked in the transistor.