Enabling large memory window and high reliability for FeFET memory by integrating AlON interfacial layer

Abstract

A thin film of AlON with a nitrogen concentration of 13% was developed as the interfacial layer (IL) of HfZrOx-based ferroelectric field-effect transistor (FeFET) memory devices on a Si substrate. Compared to the conventional SiO2/SiON IL, due to a higher dielectric constant value that allows a smaller voltage drop across it and a larger valence band offset (ΔEv) with respect to Si along with prominent passivation of Si dangling bonds that effectively suppress hole trapping, memory devices with the AlON IL demonstrate a large memory window (MW) of 3.12 V by ±4 V gate voltage sweeping, robust endurance after 105 cycles with a long pulse width of 10−4 s, and a stable MW of 2.95 V up to 10 years, standing out from other HfZrOx-based FeFET memory reported in the literature. Furthermore, the AlON IL can be integrated with HfZrOx in the same atomic layer deposition step, which greatly simplifies the process. From the device performance and process integration points of view, the AlON IL unleashes the potential of FeFET memory by enabling high reliability with a large MW.