DEPOSITION AND CHARACTERIZATION OF THIN BORON-CARBIDE COATINGS

Thin boron-carbide films were deposited using a PACVD process on Si su bstrates at room temperature. Various mixtures of B2H6/He and CH4, as well as the less hazardous B(CH3)3, have been used as process gases. T he composition of the deposited films has been correlated with the B2H 6/He/CH4 mixture used. When using B(CH3)3, the coatings were found to be slightly boron enriched compared to the gas phase stoichiometry. In both cases oxygen contaminants were additionally found (up to 5 at %) in the films. Most of the oxygen was incorporated from the residual g as at the beginning of the deposition. The coatings were hard and show ed good adherence to the substrate; no film peel-off was observed afte r exposure to air. The films have been characterized, in-situ, by elec tron spectroscopy (XPS, UPS, AES), and by other methods (AES depth pro filing, SEM, alpha-step).