SUBSTRATE BIAS EFFECTS ON DIAMOND SYNTHESIS IN A MAGNETOACTIVE MICROWAVE PLASMA

The influence of applied substrate bias on diamond film deposition has been investigated in a magnetoactive microwave discharge. The films were deposited at substrate temperatures approximately 600-degrees-C at 5 Torr on silicon (111) substrates, and were characterized by Raman spectroscopy and scanning electron microscopy (SEM). Electrons or ions are drawn from the plasma by biasing the substrate positive or negative with respect to the grounded chamber wall. Without bias, nondiamond carbon peaks are obtained in Raman spectra and ball-like features are observed in SEM micrographs. As the bias is increased, clear-cut diamond faces appear and grown diamond particles change to the (100) and (111) phase. Positively biased films are more crystalline compared to films grown with negative bias.