RESUMO
Chalcogenide-based, programmable metallization cells (PMC) cells have been characterized after exposure to increasing levels of absorbed dose (i.e., ionizing radiation exposure). We found, and show here for the first time, that total absorbed dose effects induce a slight modification of the switching phenomena with a moderate increase of the programmable low resistance state (LRS) of the PMCs after repeated switching depending on the processing conditions, while it does not impact the state programmed before exposure. We also show that an increase of the programmable high resistance state (HRS) occurs with irradiation. Such observations are discussed through correlation with crystallization observed in the concurrent X-ray diffraction (XRD) characterization of representative thin-film stacks of the PMCs. These new results are compared to previous results obtained on chalcogenide-based PMCs that did not identify/observe such effects.
RESUMO
In this work, the resistance plasticity of Cu/SiO2/W programmable metallization cell devices is experimentally explored for the emulation of biological synapses. PMC devices were fabricated with foundry friendly materials using standard processes. The resistance can be continuously increased or decreased with both dc and voltage pulse programming. Impedance spectroscopy results indicate that the gradual change of resistance is attributable to the expansion or contraction of a Cu-rich layer within the device. Pulse programming experiments further show that the pulse amplitude plays a more important role in resistance change than pulse width, which is consistent with the proposed 'dual-layer' device model. The dense resistance-state distribution, 1 V operating voltage and inherent CMOS-compatibility suggests its potential application as electronic synapse in neuromorphic computing.
