SILICON DIOXIDE DEPOSITION BY ELECTRON-CYCLOTRON-RESONANCE PLASMA - KINETIC AND ELLIPSOMETRIC STUDIES

Silicon dioxide has been deposited from electron cyclotron resonance s ilane/oxygen plasmas at temperatures below 150-degrees-C. Deposition r ates over 4000 angstrom/min have been obtained. The refractive indexes in the measuring range of 1.5-4.5 eV were found to be almost insensit ive to the different deposition rates and flux ratio regimes except in the near infrared region where small deviations from thermal oxide in dexes were observed. Etch rates and refractive indexes were very close to the thermal oxide values for low silane/oxygen flow ratios 0.025, whereas the refractive index decreased and the etch rate increased for the largest flow ratios used (0.20). After a low temperature annealin g, 500-degrees-C in nitrogen ambient, the refractive indexes reached t he best obtained values and were independent of the conditions under w hich the layers were deposited.