InGaZnO Ferroelectric Thin-Film Transistor Using HfO₂/Al₂O₃/AlN Hybrid Gate Dielectric Stack With Ultra-Large Memory Window

In this letter, HfO2/Al2O3/AlN hybrid stack capacitor with ferroelectric switching is experimentally demonstrated for the first time. The metal-insulator-semiconductor (MIS) capacitors and InGaZnO4 (IGZO) channel thin-film transistors (TFTs) with the HfO2/Al2O3/AlN hybrid gate stack are demonstrated in this letter. With the hybrid gate stack, the TFT exhibits the clear counter-clockwise memory windows (MWs) of 6.5 V, 6.2 V and 28.7 V respectively measured at 368 K, RT, and 80 K under the sweep voltage of ±40 V. Moreover, the retention over
$10^{{4}}$
s and the endurance over
$10^{{4}}$
cycles are demonstrated under the program (P)/erase (E) pulsed height of ±45 V. The results exhibit the applicable possibility of the HfO2/Al2O3/AlN stack for the high voltage memory device applications.