Improvement of charge storage and retention characteristics of HfO2 Charge-Trapping layer in NVM based on InGaZnO channels

Abstract

In recent years, with the widespread application of semiconductor thin-film memory devices, the focus of research has gradually shifted to how to fabricate memory with larger storage windows and longer retention times. This study employs the rapid thermal annealing (RTA) method to conduct multiple annealing treatments on charge trapping memory (CTM) devices that use HfO2 as the charge trapping layer, the leakage current of the device is reduced, and the negative deviation of threshold voltage is improved. During the experiments, the charge trapping layer (CTL) and tunneling layer (TL) of the devices were deposited, and a 50 nm IGZO thin film was deposited as the channel layer. The study investigates the memory performance of TFT-NVM (thin film transistor non-volatile memory) after RTA under different conditions. The results showed that the TFT-NVM with the Al2O3/HfO2/SiO2 structure has a large memory window (1.4 V) and good charge retention (>71.39 %) before O2 annealing treatment. This provides a feasible approach for future research on TFT-NVM. © 2025