DEPOSITION OF DIAMOND ON PATTERNED SILICON SUBSTRATES

We have investigated the deposition of diamond on patterned (100) sili con substrates. Trenches rectangular in shape, up to 7 mu m in depth a nd with aspect ratios (i.e. depth-to-width ratios) up to 4 have been p repared by reactive plasma etching. Diamond deposition has been perfor med by micro wave-plasma-assisted chemical vapour de position preceded by an in situ bias pretreatment to support nucleation. Scanning elect ron microscopy studies show a strong dependence of nucleation on ion b ombardment conditions. The nucleation density on vertical walls is thr ee to five orders of magnitude less than at all locations in the direc tion of ion incidence. During diamond deposition following the bias pr etreatment the growth of the layer is isotropic. The maximum film thic kness which is available within the trenches amounts to half the trenc h width and does not depend on any other parameters.