  A novel high-energy electron cyclotron resonance (ECR) ion beam deposition
(IBD) technique was used to fabricate DLC films at different ion beam energies.
The ratios of sp2/sp3 bonding in the DLC coatings were determined by Raman
spectroscopy and XPS, with the confirmation of being hydrogen-free due to the
lack of photoluminescence (PL) background in the Raman spectra. The results
indicate that the sp3 percentage ranges from 45% - 85% for the ECR-IBD
fabricated DLC films in this study. Monte-Carlo based SRIM simulation was used
to extract the energy and angular distribution of the sputtered particles from
the carbon target and correlate it to the highest sp3 fraction in the
manufactured ECR-IBD DLCs. This study demonstrates a method of depositing DLC
thin films under ambient conditions (room temperature with no post-annealing or
additional bias voltage applied) which produces high-sp3 coatings (higher than
those traditionally reported for other sputtering methods) suitable for
applications where high quality DLC coatings are required.
