CHEMISTRY OF THE PRECURSORS AND THE PROCESSES

This topic aims to study the metallorganic precursor selection and design for ALD, the numerical modeling of reactors from lab to industrial scale, the design of the couple precursors/second reactant and the experimental good practices in ALD. Modeling and fundamental science can also be fed with in-situ characterizations of the ALD process, so this topic will also develop the crucial complementarities between process knowledge and relevant in-situ characterizations (Ellipsometry, Raman, Curvature, etc.) that are particularly difficult to manage in ALD due to the very thin layers considered.

ALD is now a well mastered process with many examples of successful industrial outputs, so a great effort will be made to highlight and develop new processes derived from ALD. Taking inspiration from the broad range of CVD processes, DLI ALD (Direct Liquid Injection ALD), ALE (Atomic Layer Etching), SALD (Spatial and Selective ALD) must now be pushed toward industry by upscaling, process optimization and modeling.

Numerical modeling addresses multiple time and length scales. It can support the development of precursors at atomic scales to invent new chemical routes or new ligands for improving precursors volatility or reactivity at low temperature. It can also support industrial upscaling and full process optimization. Modeling will be used as a supporting tool to enhance the reliability and efficiency of ALD process, the good choice of precursors and the most relevant way to deliver them.

Modeling is not able to predict everything, so good experimental practices and methods are also welcomed in this topic. In particular, the Design of Experiments method (DOE) will be introduced as a powerful tool to save time and money during ALD process development, in addition to numerical  modeling.

Example of numerical simulation of fluids in a ALD reactor equipped with specific in-situ caracterisation tools. Optical ports are protected by Ar flow.

Raphaël Boichot, SIMaP

Stéphane Danièle, IRCELyon

Carmen Jimenez, LMGP