MPCVD DIAMOND DEPOSITION ON BIAS PRETREATED POROUS SILICON

We have investigated the nucleation and growth of chemical vapour deposited diamond films on bias seeded porous silicon. Nucleation enhancement on porous silicon over as-grown silicon after bias pretreatment was found. Porous silicon, with pore densities of the order of 10(10)-10(11) cm(-2) and a high density of sharp pore edges and corners, favours nucleation. Cathodoluminescence (CL) and micro-Raman spectroscopy demonstrate that diamond films grown on porous silicon exhibit good crystalline structure and show less stress than their counterparts on as-grown silicon under the same deposition conditions. Secondary ion mass spectroscopy (SIMS) analysis shows that carbon penetrates into porous Si during bias seeding and deposition. A possible explanation for the observed nucleation enhancement, based on the surface structure of porous silicon, is given.