Impact of the interface layer on the cycling behaviour and retention of ferroelectric hafnium oxide

Maximilian Lederer,Lukas M Eng,Kati Kühnel,Jennifer Emara,Yannick Raffel,Thomas Kämpfe,David Lehninger,Konstantin Mertens,Alireza M Kia,Tarek Ali,Ricardo Olivo,Konrad Seidel

doi:10.1557/s43580-021-00102-4

Maximilian Lederer, Lukas M Eng + Show 10 more

Open Access

https://doi.org/10.1557/s43580-021-00102-4

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Abstract

Reliability is a central aspect of hafnium oxide-based ferroelectric field effect transistors (FeFETs), which are promising candidates for embedded non-volatile memories. Besides the device performance, understanding the evolution of the ferroelectric behaviour of hafnium oxide over its lifetime in FeFETs is of major importance for further improvements. Here, we present the impact of the interface layer in FeFETs on the cycling behaviour and retention of ferroelectric silicon-doped hafnium oxide. Thicker interfaces are demonstrated to reduce the presence of antiferroelectric-like wake-up effects and to improve endurance. However, they show a strong destabilisation of one polarisation state in terms of retention. In addition, measurements of the Preisach density revealed additional insight in the wake-up effect of these metal-ferroelectric-insulator-semiconductor (MFIS) capacitors.Graphic abstract

Highlights

Ferroelectric field effect transistors based on hafnium oxide have become a viable option as embedded non-volatile memory solution due to their high coercive field as well as their compatibility to complementary metal-oxide-semiconductor (CMOS) processes [1]
The interface layer has a major impact on the behaviour and reliability of ferroelectric hafnium oxide in MFIS capacitors, and field effect transistors (FeFETs)
Thin interface layers result in asymmetric wake-up, during which hystereses with ferroelectric and antiferroelectric-like behaviour on either side of the hysteresis, respectively, can be observed

Summary

Introduction

Ferroelectric field effect transistors based on hafnium oxide have become a viable option as embedded non-volatile memory solution due to their high coercive field as well as their compatibility to complementary metal-oxide-semiconductor (CMOS) processes [1]. It has been reported that the interface layer is changing in thickness and chemical composition during the dopant activation and crystallisation anneal of the ferroelectric [4, 5]. How this affects the cycling behaviour as well as retention of ferroelectric HSO layers in MFIS stacks is investigated in this article.

Results

Conclusion