Although
two-dimensional (2D) nanomaterials are promising candidates
for use in memory and synaptic devices owing to their unique physical,
chemical, and electrical properties, the process compatibility, synthetic
reliability, and cost-effectiveness of 2D materials must be enhanced.
In this context, amorphous boron nitride (a-BN) has emerged as a potential
material for future 2D nanoelectronics. Therefore, we explored the
use of a-BN for multilevel resistive switching (MRS) and synaptic
learning applications by fabricating a complementary metal-oxide-semiconductor
(CMOS)-compatible Ag/a-BN/Pt memory device. The redox-active Ag and
boron vacancies enhance the mixed electrochemical metallization and
valence change conduction mechanism. The synthesized a-BN switching
layer was characterized using several analyses. The fabricated memory
devices exhibited bipolar resistive switching with low set and reset
voltages (+0.8 and −2 V, respectively) and a small operating
voltage distribution. In addition, the switching voltages of the device
were modeled using a time-series analysis, for which the Holt’s
exponential smoothing technique provided good modeling and prediction
results. According to the analytical calculations, the fabricated
Ag/a-BN/Pt device was found to be memristive, and its MRS ability
was investigated by varying the compliance current. The multilevel
states demonstrated a uniform resistance distribution with a high
endurance of up to 104 direct current (DC) cycles and memory
retention characteristics of over 106 s. Conductive atomic
force microscopy was performed to clarify the resistive switching
mechanism of the device, and the likely mixed electrochemical metallization
and valence change mechanisms involved therein were discussed based
on experimental results. The Ag/a-BN/Pt memristive devices mimicked
potentiation/depression and spike-timing-dependent plasticity-based
Hebbian-learning rules with a high pattern accuracy (90.8%) when implemented
in neural network simulations.