Initial growth phase of diamond thin films observed by thermal emission spectrometry

Pyrometric interferometry has been performed in the formation of diamond crystals and films synthesised on pretreated single silicon substrates by a microwave plasma assisted chemical vapour deposition (MPCVD) technique. The growth mode of this material induces particular variations of the emissivity ratio epsilon/epsilon(0) that we an able to simulate theoretically, taking into account the nucleation mode (Volmer-Weber), the nucleation density N and the growth rate nu of the diamond crystallites. The comparison between the experimental and the theoretical curves of the epsilon/epsilon(0) variations allows us to understand better the first stage of the CVD diamond formation in terms of kinetic and nucleation density. Finally, the real-time monitoring of these parameters is a very attractive objective for the precise control of the deposition process, for which the first stages are crucial for the subsequent diamond film quality. (C) 1997 Elsevier Science S.A.