Amorphous diamond-like carbon films have been grown by pulsed laser deposition using a graphite target both with and without an atomic hydrogen beam incident on the growing film. Films grown with the hydrogen beam showed resistivity nearly two orders of magnitude higher than the films grown without hydrogen. Raman scattering confirmed a higher degree of sp(3) bonding in films exposed to hydrogen atoms during growth. Films grown without hydrogen but exposed to the hydrogen beam after growth showed a significant increase in resistivity after exposure. (C) 1998 Elsevier Science S.A. All rights reserved.