Deposition from Supersonic Beams (SuMBE): a Kinetic Approach for Controlling Thin Film Properties

Abstract

Supersonic beams of organic molecules seeded in light carrier gases are a viable method to control the deposition of highly ordered thin films, to activate kinetically chemical reactions to functionalize surfaces or to synthesize hybrid compounds. The advantage of supersonic molecular beam deposition (SuMBE) with respect to the more standard OMBE/OMBD method is the control of the energetic parameters of the precursors that we have shown to give an unprecedented control on structural, morphological and hence functional properties in the deposition of organic thin films. The basic mechanism is envisaged to be a sort of local annealing activated by the kinetic energy of the molecules that collides with the surface. Depending on the molecular precursor used and on the kinetic energy achievable this same method can be exploited to activate reactivity at the surface and hence to synthesize different structures. Here we report on a few examples including the deposition of highly ordered organic thin films of pentacene, the synthesis of SiC at moderate temperatures and the functionalization of inorganic nanostructured materials such as TiO2.