High throughput heterostructures characterization for hafnia-based microelectronics

A CEA-CNRS joint laboratory, SPEC has internationally recognized expertise in photoemission based techniques in both laboratory and synchrotron environments for the understanding of functional oxides for emerging microelectronics technologies. The laboratory develops operando experiments to study the response of materials to the application of electric fields and mechanical stress. The LENSIS laboratory has a long experience in photoelectron spectroscopy using synchrotron radiation (Daresbury SLS, LURE, ESRF, ELETTRA, BESSY, SOLEIL, ANKA, SLS-Villigen, PETRA-III) and in PEEM and LEEM instrumentation. Current research themes cover ferroelectric oxides and their surface and interface chemistry in prototypical heterostructures and devices.

https://www.lensislab.com/

Ferroelectricity in HfO₂ thin films (10nm) was unveiled 12 years ago,[1] changing the paradigm of ferroelectric memories due to CMOS compatibility and scalability of hafnia. Even though a significant amount of work has been published during the last decade, the optimization of the ferroelectric properties remains complex because of the metastable nature of orthorhombic phase. Improving device performance therefore requires the simultaneous optimisation of both the individual layers (thickness, stoichiometry, crystallinity…) and their metastructure i.e. the optimization of the stack as a whole. We will develop a combinatorial analysis providing lateral resolution on the scale of the expected chemical and physical variations and depth resolution on the scale of the implemented heterostructures. The advanced characterization methods employed will use Photoemission electron microscopy (PEEM) in laboratory environment and Hard X-ray Photoelectron spectroscopy (HAXPES) with synchrotron radiation. The aim of the project is to validate a complete artificial intelligence assisted, high throughput synthesis / characterization chain leading to accelerated production of optimized microelectronic devices and generation of material database resources.

Within the framework of the Diadem MicroElec project, funded by the Agence Nationale de la Recherche (ANR), two advanced characterization platforms will be implemented here. PEEM in laboratory environment will use a high intensity focused X-ray source adapted for imaging of multiple ferroelectric capacitors (FeCAPs). Dedicated sample-holders will allowing wiring of multiple FeCAPs for operando HAXPES analysis with synchrotron radiation. The combinatorial analysis of the resulting datasets will probe materials with the required range of Dx and Dz and provide full physical chemical screening of operational prototypical structures. Samples will be elaborated in close collaboration with the CEA/Léti (Grenoble). Experiments will be carried out in CEA Saclay and in synchrotron radiation centres, notably Soleil synchrotron.

Experimental scientist

PhD in solid state physics, surface chemistry, nanosciences

Knowledge of oxide materials, ferroelectrics

Experience in photoelectron spectroscopy preferred

Core level XPEEM imaging of microscopic HfO2-based capacitors