Implementation of Short-Term Plasticity and Long-Term Potentiation in a Synapse Using Si-Based Type of Charge-Trap Memory

We present a novel silicon-based type of charge-trap memory using Al/HfO₂/Al₂O₃/Si₃N₄/Si structure mimicking memory functions in a biological synapse. The quantity of the trapped charge in the proposed Al₂O₃/HfO₂/Si₃N₄ stack is estimated by measuring the capacitance over time, which can be regarded as synaptic weight changes. By applying repeated voltage pulses at periodic intervals of different times, reliable short-term plasticity and long-term potentiation properties are obtained along with their transition behavior. This architecture is compatible with the CMOS process and shows great promise as an essential part for the implementation of an electrical neuromorphic system.