Reactive sputter-deposition of oxygenated amorphous carbon thin films in Ar/O2

Oxygenated amorphous carbon thin films were deposited by DC magnetron sputtering using various argon and oxygen process gas mixtures. The X-ray diffraction data indicated that the predominantly amorphous films had more defined peaks with a higher partial pressure of oxygen. Results indicated that use of oxygen in the working gas enhanced the crystalline nature of the films. Scanning electron and atomic force microscopy revealed that the surface roughness and film topography differed with the oxygen process gas variations. X-ray photoelectron spectroscopy revealed increased surface oxygen content with higher oxygen concentration in the working gas. Raman spectroscopy results suggested that the increased oxygen in the films may have led to a higher percentage of sp³-bonded carbon atoms. The growth rate (deposition rate) of the films decreased as the amount of oxygen increased. This decreased deposition rate was associated with an oxygen etching of the film.