Abstract
Diamondlike carbon (DLC) is an amorphous carbonaceous allotrope, which is composed of sp2 carbon, sp3 carbon, and hydrogen. This paper reviews the authors' analysis of the surface chemical structure of DLC films by x-ray photoelectron spectroscopy (XPS). The C 1s spectra of the DLC films were analyzed by the Doniach-Šunjic function convoluted with a Gaussian function and were decomposed into four components, which take account of the differences between sp2 and sp3 carbons and between carbon-carbon and carbon-hydrogen bonds. This analysis agrees with actual hydrogen distribution analyzed by high-resolution elastic recoil detection (ERD). On the other hand, a modified gas-phase chemical derivatization (GCD) method with the help of a simple mathematical treatment is also reviewed in order to analyze oxygen-related surface functional groups on DLC surfaces. The method takes account of the side reactions which complicate the analysis and has well explained the oxidation process of the DLC surface. These discussions conclude that XPS would be a comprehensive analytical tool for the DLC surface.
