Synaptic Plasticity Modulation of Neuromorphic Transistors through Phosphorus Concentration in Phosphosilicate Glass...

Area of Science:

• Materials Science
• Neuroscience
• Electrical Engineering

Background:

• Neuromorphic systems aim to mimic biological brain functions.
• Synaptic transistors are key components for artificial neural networks.
• Controlling synaptic plasticity is crucial for neuromorphic computing.

Purpose of the Study:

• To investigate the effect of phosphorus (P) concentration in phosphosilicate glass (PSG) on synaptic transistor characteristics.
• To demonstrate the feasibility of tuning synaptic behavior by adjusting P concentration in PSG.
• To explore the potential of PSG-based synaptic transistors for neuromorphic applications.

Main Methods:

• Fabrication of PSG-based electrolyte-gate synaptic transistors with varying P concentrations.
• Characterization using frequency-dependent capacitance (C-f) curves and Fourier transform infrared spectroscopy (FTIR).
• Analysis of device performance through double-sweep transfer curves, excitatory post-synaptic currents, and learning simulations (Modified National Institute of Standards and Technology).

Main Results:

• Increased PSG electric double-layer capacitance with rising P concentration at 10³ Hz.
• Correlation between P concentration, P-OH structure, and device capacitance.
• Tunable hysteresis window and synaptic behaviors (potentiation, depression) by adjusting P concentration.
• Successful demonstration of neuromorphic system feasibility using Modified National Institute of Standards and Technology learning simulations.

Conclusions:

• Phosphorus concentration in PSG is a critical parameter for controlling synaptic transistor behavior.
• Adjusting P concentration allows for selective mimicry of human synaptic signal strength.
• This approach offers a promising pathway for developing advanced neuromorphic systems.