BORON INCORPORATION EFFECTS IN CVD DIAMOND FILM GROWTH

We report the p-doping of MWCVD diamond films with a novel gaseous source of boron : trimethylboron B(CH3)(3). Polycrystalline diamond films with a wide range of boron contents were obtained. Surface SEM analysis showed morphological differences related to the boron content in the films. Raman spectra of samples with boron content lower than 0.2 at% showed a decrease of the non-diamond phases found in undoped samples. The Raman peak of diamond disappeared in films of 0.7 at% of boron. The lattice parameter of diamond increased with increasing boron content. Structural and electrical analysis indicated the predominant substitutional or interstitial boron incorporation into the films, depending on the boron concentration.