Hydrogen-free amorphous carbon (a-C) films prepared by RF magnetron sputter
ing were deposited on Si substrates in thin films, at various negative bias
voltages V-b, (i.e. Ar-ion energies), and in thick layered-structure films
with alternative values of V-b. The main purposes of this work are to pres
ent preliminary results concerning the effect of Ar-ion bombardment during
deposition on the elastic properties of thin a-C films with Ar+ energies in
the range 30-200 eV, and the adhesion failure which limits their thickness
and usefulness for practical applications, and the enhancement of hardness
and scratch resistance of sputtered a-C films developed in a layered struc
ture. The results show a significant improvement in the elastic properties
of layered structure films and their stability. The combination of high har
dness and relative low elastic modulus which the layered films exhibit make
them more resistant to plastic deformation during contact, as confirmed by
scratch testing. (C) 1999 Elsevier Science S.A. All rights reserved.