Plasma treatment effects on hydrogenated amorphous carbon films prepared by plasma-enhanced chemical vapor deposition

When hydrogenated amorphous carbon (a-C:H) films are deposited by a radio frequency (RF; 13.56 MHz) glow discharge system, their properties can be significantly affected by RF power input at deposition. Furthermore, the hydrogen content in the a-C:H films will be decreased in the postdeposition plasma treatment. This study investigated the effects of plasma input at deposition and postdeposition plasma treatment on the resulting film properties of a-C:H films. Atomic force microscopy (AFM) was employed to detect the surface roughness of the plasma-enhanced chemical vapor deposition (PECVD) a-C:H films. Raman spectroscopy was employed to determine the hydrogen concentration as well as the tetrahedral and trigonal bondings associated with C–H bond. The Raman analysis results suggested the occurrence of a higher degree of structural order in the sp2 lattice of the well plasma-treated a-C:H films.