Structural and optical properties of plasma-deposited amorphous hydrogenated oxygenated carbon films

摘要

Amorphous hydrogenated oxygenated carbon (a-C:O:H) films were deposited from C 6H 6/O 2/ He/Ar mixtures in a deposition system fed rf power. The principal variable was the percentage of oxygen in the feed, R ox. Film structure and composition were investigated as a function of R ox using transmission infrared- and x-ray photoelectron spectroscopy. To some degree, greater values of R ox lead to greater incorporation of oxygen functionalities such as OH, C-O, and C=O into the deposited material. As revealed by ultraviolet-visible spectrophotometry, the optical gap E 04 increased from∼3.1 to ∼3.5 eV as R ox was increased from 0% to ∼50%. Semiempirical methods (PM3 and ZINDO-S/CI) allow modeling of the dependence of E 04 on 7 ox. Broad agreement between the results of the experimental and theoretical analyses was obtained. © 1997 American Vacuum Society.