S. Barrat et al., A MICROSTRUCTURAL AND MORPHOLOGICAL-STUDY OF DIAMOND CRYSTALS AND FILMS ELABORATED BY MICROWAVE PLASMA-ASSISTED CHEMICAL-VAPOR-DEPOSITION, Surface & coatings technology, 59(1-3), 1993, pp. 330-337
In this work, morphological and microstructural characterization of co
ntinuous films and isolated crystals of diamond obtained by microwave
plasma-assisted chemical vapour deposition was carried out using trans
mission electron microscopy and scanning electron microscopy to correl
ate the diamond morphology and nucleation density with physical parame
ters of the deposition procedure such as gas composition (argon or oxy
gen additions to a CH4-H-2 system), temperature variations and pretrea
tment of the silicon substrate. This study was carried out using a par
ticular plasma configuration which allows temperature and plasma densi
ty gradients. We point out that good quality diamond film can be achie
ved by a compromise between a low substrate temperature (obtained by d
ecreasing the microwave power) and good plasma reactivity (obtained by
adding gases such as O2 or argon). In order to obtain a continuous di
amond film, it is necessary to scratch the substrate with abrasive par
ticles; we demonstrate that the nucleation density strongly depends on
the nature of these particles.