Improvement of mechanical properties of a-C:H by silicon addition

The structure of a hard a-C:Si:H deposited by RF reactive sputtering from a graphite target in an argon-silane atmosphere is analysed. It is shown that Si and C atoms are intermixed and form a rigid network. The details of the deposition process are discussed and the crucial role of argon evidenced. Argon atoms dehydrogenate silane to form SiH groups, which have a high sticking coefficient and a low surface mobility. These groups become centres of nucleation. The energy of argon ions impinging on the growing surface is important in determining a good intermixing of carbon and silicon and the removal of voids. (C) 1997 Elsevier Science S.A.