Electron spectroscopy of ion beam and hydrocarbon plasma generated diamondlike carbon films

Abstract

Mechanically hard, electrically insulating (diamondlike) carbon thin films have been produced by low energy carbon ion beam deposition and by decomposition of butane gas. Deposition parameters are presented for these two methods. The ion beam films can be produced with or without a secondary discharge in the ion source and the parameters are given for these two modes of operation. ESCA and electron energy loss (EELS) techniques have been used to examine the electronic character of these films. ESCA carbon (1s) spectra show that the films are composed mostly of C–C bonds and that a negative bias is important to eliminate C–H bonds from the butane generated films. EELS data show that the films are more diamondlike in that the strong graphitic feature at 6.5 eV is not evident in these films. Among the other measured properties of these films, the refractive index (2.3 at 5 μm) and hardness (1850 knoop) are in keeping with the diamondlike character of these films.