Chemical analysis of the plasma-polymerized diphenyl thin films

Abstract

Plasma-polymerized diphenyl (PPDP) thin films were prepared by glow discharge technique. The PPDP films were characterized by scanning electron microscopy (SEM), elemental analysis, infrared (IR) spectroscopy, Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). The surface morphology of the PPDP film is observed to be uniform and pinhole-free. The IR analysis reveals that the structure of PPDP thin film is different from that of the monomer diphenyl. The atomic ratios, O/C and N/C, of the PPDP film surfaces are found to be 0.25 and 0.04 by AES and those by XPS are 0.30 and 0.05, respectively. It is demonstrated that the chemical characteristics of the PPDP thin films, as revealed by AES and XPS, are not much different. It is found that the surface and bulk atomic concentrations of the constituent elements are not identical.