Tunnel Thin-Film Transistor Featuring Ferroelectric Gate Stack for Synaptic Applications

The tunnel thin-film transistor (tunnel-TFT) with polycrystalline-silicon (poly-Si) channel and ferroelectric gate dielectric HfZrO
x
is fabricated to demonstrate the synaptic characteristics of potentiation and depression in conductance (G
d
). Compared to conventional ferroelectric TFT (Fe-TFT), the ferroelectric tunnel-TFT exhibits much lower conduction current and G
d
due to its unique carrier transport mechanism: interband tunneling. The low conduction current and G
d
of ferroelectric tunnel-TFT can effectively reduce the power dissipation of neuromorphic computing circuits. Consequently, the ferroelectric tunnel-TFT is demonstrated to exhibit a 5-bit function, low asymmetry, and high G
d
ratio to meet the requirement of a high recognition rate of neuromorphic computing.