Ferroelectric random access memories (FeRAM) based on hafnium zirconium oxide (HZO) are intrinsically ultra-low power thanks to the voltage switching mechanism, the scaling potential of HZO to below 10 nm and full CMOS compatibility. In addition, they demonstrate low latency necessary for a wide variety of edge logic and memory applications. Understanding the underlying mechanisms and kinetics of ferroelectric domains switching is essential for intelligent FeRAM design and optimal performance.

This thesis focuses on the comprehensive characterization of ferroelectric (FE) domains in ultra-thin HZO films. The student will use several surface imaging techniques (piezoelectric force microscopy, PFM, low energy electron microscopy, LEEM, and x-ray photoemission electron microscopy, PEEM) combined with advanced operando characterization methods (time-resolved detection coupled with synchrotron radiation) for this purpose. This project will mark an important progress on the fundamental research on the polarization switching mechanisms of ultra-thin hafnia-based FE layer, elucidating the specific effects of the metal electrode/FE layer interface in the electrostatic behaviour of the studied capacitors. It will ultimately allow a significant breakthrough on the industrial development of ferroelectric emerging memories, essential for large-scale artificial intelligence (AI) applications.