The influence of silicon substrate cleaning prior to the deposition of
diamond-like carbon films has been investigated as well as the compos
ition of the coating/substrate interface which governs the adhesion of
the deposits. Three different cleaning procedures have been used: arg
on plasma cleaning, CF4 dry etching and HF wet cleaning. In-situ ellip
sometry has provided real-time evolution of the surface and interface
during the plasma treatment and XPS analysis has been used to get info
rmation about the chemical structure of the interface. Ar cleaning has
induced silicon lattice damages and the native oxide was not etched.
The oxide removal is achieved using CF4 dry etching. Moreover CF4 over
etching leads to Si-C bond formation.