Ferroelectric-Like Non-Volatile FET With Amorphous Gate Insulator for Supervised Learning Applications

We experimentally demonstrate ferroelectric-like non-volatile field-effect transistor (NVFET) with the amorphous Al
₂
O
₃
gate insulator for artificial synapse applications. The switchable polarization (
P
) is attributed to the voltage modulation of mobile ions in the gate insulator. The ferroelectric-like NVFETs integrated with 3 nm and 6 nm-thick Al
₂
O
₃
dielectrics demonstrate the capability to mimic various synaptic behaviors including long-term potentiation (LTP), long-term depression (LTD), and spike-timing-dependent plasticity (STDP), under different types of electrical stimuli to the gate electrode. To verify the application of the ferroelectric-like transistors in the Spike Neural Network (SNN), the online training has been carried out based on the synaptic characteristics of the devices, and a decent accuracy (>80%) is achieved for fixed-amplitude ±3 V/100 ns potentiation/depression pulses.