Regensburg 2013 – scientific programme

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O: Fachverband Oberflächenphysik

O 10: Nanostructures at Surfaces I

O 10.7: Talk

Monday, March 11, 2013, 12:00–12:15, H45

Dynamics of Adsorbed EBID Precursors (W(CO)6 and Co2(CO)8) and their Fragments — •Muthukumar Kaliappan^1,2, Harald Jeschke¹, and Roser Valenti¹ — ¹Institut für Theoretische Physik, Max-von-Laue-Straße 1, 60438, Frankfurt am Main, Germany — ²muthukumar.kaliappan@gmail.com

We investigate the fundamentals of the growth process of nano composites in electron beam induced deposition (EBID) process using first principles molecular dynamics simulation. We compare the behavior of two carbonyl precursors (W(CO)₆ and Co₂(CO)₈) on two different SiO₂ surfaces (fully hydroxylated (FOH) and partially hydroxylated (POH)) that represent realistic EBID conditions. These precursors are commonly used to obtain tungsten and cobalt composites and our 20 ps simulations illustrates that these precursors are stable and mobile on the FOH surfaces behaving similar to the gas phase molecules. However, they fragment on POH surfaces upon their interaction with the surface active sites and tend to remain localized on their bonding sites. Apart from changes in the orientation, they show no tendency for the reformation of the parent precursor molecule. Vibrations of these adsorbed species are studied by computing their power spectrum from the trajectory that provides crucial information on the nature of adsorbed precursor fragments.