| AVS 57th International Symposium & Exhibition | |
| Advanced Surface Engineering | Tuesday Sessions |
| Session SE-TuM |
| Session: | Hard and Nanostructured Coatings |
| Presenter: | F. Nahif, RWTH Aachen University, Germany |
| Authors: | K. Jiang, RWTH Aachen University, Germany F. Nahif, RWTH Aachen University, Germany K. Sarakinos, Linköping University, Sweden S. Konstantinidis, University of Mons, Belgium D. Music, RWTH Aachen University, Germany J.M. Schneider, RWTH Aachen University, Germany |
| Correspondent: | Click to Email |
In this study, we deposit Al2O3 films using plasma assisted chemical vapor deposition (PACVD) in an Ar-H2-O2-AlCl3 atmosphere and by filtered cathodic arc.
During PACVD a novel generator is employed delivering four times larger power densities than those obtained in conventional PACVD approaches. This mode of operation enables the increase of the efficiency of the AlCl3 dissociation in the gas phase, as well as a more intense energetic bombardment of the growing film . We demonstrate that these deposition conditions allow for the growth of dense films a-Al2O3 with negligible Cl incorporation and elastic properties similar to those of the bulk a-Al2O3 at a temperature of 560 ±10 °C.
a-Al2O3 films are deposited employing a monoenergetic Al+ beam generated by a flitered cathodic arc. A critical Al+ ion energy of 40 eV for the formation of the a-Al2O3 phase at a substrate temperature of 720 °C is determined. This energy is used as input for classical molecular dynamics and Monte-Carlo based simulations of the growth process, as well as ab initio calculations. The combination of theory and experiment indicates that in addition to the well known surface diffusion the previously non considered diffusion in sub-surface regions is an important atomistic mechanism in the phase formation of Al2O3.