Time-dependent in-situ Raman observation of atomic hydrogen etching on diamond-like carbon films

In-situ time-dependent Raman spectra were measured on the thermal annealing of diamond-like carbon films produced by Pulsed Laser Deposition (PLD-DLC), with or without the presence of atomic hydrogen etching. It was found that annealing transformed DLC films into a graphitic structure in both cases and this transformation was completed within 30 min of annealing. Atomic hydrogen etches away the G*=1500 cm(-1) band, revealing the existence of the D*= 1200 cm(-1) band. Both G*- and D*- phases are as stable as graphite during thermal annealing. These observations separate the effects of thermal annealing and annealing with atomic hydrogen etching on diamond-like carbon films. (C) 2002 Elsevier Science B.V. All rights reserved.