KINETICS AND COMPOSITIONAL DEPENDENCE ON THE MICROWAVE-POWER AND SIH4N2 FLOW RATIO OF SILICON-NITRIDE DEPOSITED BY ELECTRON-CYCLOTRON-RESONANCE PLASMAS/

Silicon nitride layers have been deposited at a low temperature, 150-d egrees-C, in an electron cyclotron plasma from nitrogen and silane as gas precursors. Deposition conditions have been varied in a wide range . Nitrogen flows from 25 to 400 sccm and silane flows from 2.5 to 35 s ccm have been used in our experiments. The microwave power was varied from 100 to 1500 W. The result of the nitride growth kinetics show str ong dependence on the silane to nitrogen flow ratio and on the microwa ve power. For large flow ratios and small powers the kinetics exhibits a nearly linear behavior whereas for low flow ratios and high powers a saturated regime was observed. Ellipsometry, infrared spectroscopy, and etch rate studies showed that the best material quality, 95% Si3N4 , is obtained in the saturated regime for the lowest flow ratios and t he highest powers used.