DIAMOND SEED INCORPORATION BY ELECTROCHEMICAL TREATMENT OF SILICON SUBSTRATE

Ultrafine diamond powders (UFD) were incorporated into Si substrates b y electrochemical etching in a HF:C2H5OH:H2O solution containing UFD. Produced by this method, thin layers have shown optical and photolumin escence properties being typical for porous silicon. On the treated Si wafers a significant increase of the diamond nucleation density (comp ared with the substrates prepared by a common scratching method and an odized in electrolyte without UFD) has been reached. Another important advantage was a possibility to decrease significantly the substrate t emperature (down to 500 degrees C) for CVD diamond deposition due to a low thermal conductivity of the porous silicon layer. (C) 1997 Elsevi er Science S.A.