Hydrogen effects on the post-production modification of diamond-like carbon produced by pulsed laser deposition

This work utilizes Raman spectroscopy to examine the thermal annealing of diamond-like carbon (DLC) films produced by pulsed laser deposition (PLD). Post-production modification of DLC films by atomic hydrogen etching reveals distinct results and is observed for the first time. Both ex-situ and in-situ thermal annealing and annealing with atomic hydrogen on the as-prepared DLC samples are compared herein. The Raman spectra reveal that the typical D- and G-bands evolve from unresolved to well separated above 400 degreesC as the temperature increases from room temperature to 700 degreesC, Atomic hydrogen enhances the annealing process at temperatures above 500 degreesC, Thermal annealing transforms the DLC films into graphitic structures while atomic hydrogen etches away the disordered carbons according to both the ex-situ and in-situ Raman spectra. (C) 2001 Elsevier Science B,V. All rights reserved.