DYNAMIC BEHAVIOR OF CARBON ULTRATHIN-FILM FORMATION

We present here investigations of the initial steps in the formation o f ultrathin carbon films on a carbon highly oriented pyrolytic graphit e substrate by the deposition of low energy carbon ions at temperature s from ambient to 300 degrees C. We used an ultrahigh vacuum scanning tunneling microscopy to observe the growth of these films. At a nanome ter scale, we revealed a roughening transition of the island's growth, from lateral to tridimensional growth. Also, here we introduce the sc aling analysis of roughness to describe the evolution of the morpholog y of the interface during growth. The ultrathin film formation mechani sms are studied as a function of ion density and annealing. (C) 1998 A merican Institute of Physics. [S0021-8979(98)01416-9].