Modeling The First Activation Stages of the Fe(hfa)2 TMEDA CVD Precursor on a Heated Growth Surface

Gloria Tabacchi, Ettore Fois, Davide Barreca, Giorgio Carraro, Alberto Gasparotto, Chiara Maccato
  • December 2015, Wiley
  • DOI: 10.1002/9781119211662.ch10

Behaviour of molecular precursors for Fe2O3 nanomaterials

What is it about?

Iron oxide-based functional nanostructures are important technological materials that can be obtained with high purity and desired composition and morphology by Chemical Vapor Deposition (CVD). Understanding the decomposition of the molecular precursor and the formation of the new material would further improve the fabrication process. This goal can be achieved by using advanced computational methods. Here, we studied the behaviour of a typical Fe(II) precursor molecule on a model CVD growth surface by first principles molecular dynamics simulations. Beside determining the physisorption geometry, we observed an interesting behaviour of the precursor molecule under high- temperature conditions, which are typically adopted in the deposition experiments.

Why is it important?

We evidenced a fast rolling motion of the Fe(II) precursor over the heated surface - a behaviour already observed for similar molecules, containing zinc and copper. This motion, induced by the high temperature of the heated surface, significantly perturbed the precursor molecule and suggested that its first fragmentation step should be the loss of the most loosely bound ligand (diamine, in this case). Hence, molecular rolling on the growth surface can explain the deposition behavior of an important class of CVD precursors.

Perspectives

Gloria Tabacchi
university of insubria

We showed that properties and reactivity of an important series of Chemical-Vapor Deposition precursors greatly depend on the chemical nature of the metal center M. In particular, all such complexes share a similar octahedral structure, but they break apart in different ways. Such differences have been explained by computer simulations. This knowledge will be very important for understanding the first steps of the deposition process, and in particular how the metal center binds with the atoms of the growth surface.

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http://dx.doi.org/10.1002/9781119211662.ch10

The following have contributed to this page: Gloria Tabacchi