Film deposition using a non-thermal microwave-generated microplasma at atmospheric pressure

Summary form only given. A microplasma based on a microstrip split-ring resonator¹ (SRR) discharge has been used in atmospheric pressure gas mixtures to deposit hard films onto glass substrates. The SRR can generate steady-state plasma densities² on the order of 10¹⁴ cm^-3, potentially allowing access to unique materials-processing parameter spaces. Films were deposited on glass substrates using a feedstock of acetylene and helium gases at atmospheric pressure. Typical acetylene concentrations ranged from 0.025%-0.1%. Acetylene concentration and substrate separation from the SRR electrodes were found to be the dominant parameters in determining film quality. The separation roughly controls the ion flux to the substrate. Our results suggest that large ion fluxes are required to deposit non-polymeric films. At optimal conditions, hard, chemically resistant films believed to be diamond-like carbon were deposited on the substrates. While the present experiments were performed using a single SRR, one- and two-dimensional arrays of microwave resonators have been developed that could allow high volume roll-to-roll style processing.