In Situ Monitoring and Characterization of Superhard Thin-Film Growth Under Non-Equilibrium Conditions
Final rept. 7 Jun 1996-6 Oct 2000
ARIZONA STATE UNIV TEMPE
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We have developed new approaches to synthesize superhardultrastrong thin films and coatings by chemical vapor deposition CVD of unimolecular precursors, and to monitor and characterize the film-growth process in situ and in real time. To this end, we have designed and constructed an ultrahigh vacuum CVD chamber fitted with energy-dispersive x-ray reflectivity XRR and multiple- beam optical stress sensor MOSS for in situ monitoring of surface morphology and stress evolution of the films under growth. Both of these techniques were applied to the CVD growth of boron and GaN films. We have synthesized novel precursors of C3N3P, Si4CN4, LiBC4N4, BC3N3, BeC2N2, MgC2N2 for CVD growth of films with properties of superhardness. We have also deposited thin films by CVD with the composition of Zr-B-Si-N via reactions of ZrBH44 with SiH4, and ZrBH44 with NSiH34. The elastic constants cli and c44 of these films measured by Brillouin scattering in collaboration with Prof. Sooryakumar of Ohio State University produced results suggesting that films and coatings based on the Zr-B-Si-N system exhibit promising superhard properties.
- Inorganic Chemistry
- Solid State Physics
- Coatings, Colorants and Finishes