CHARACTERIZATION OF BIASED ELECTRON-CYCLOTRON RESONANCE DEPOSITED OXIDES

An extensive study characterizing the properties of silicon oxide films deposited using biased electron cyclotron resonance (ECR) plasmas was performed. The ECR system provided microwave plasma excitation at 2.45 GHz, at power levels from 200 to 1000 W. Confinement of the resonant plasma was achieved using two independent current-controlled electromagnets. The deposition gases were O2, N2O, and dilute silane in Ar; process flow rate, pressure, and microwave power were held constant. Radio frequency power was applied to the substrate electrode to attain a bias that was varied from 0 to 300 V to affect film characteristics. The uniformity, refractive index, stress, and dry and wet etch rates of ECR oxides were evaluated and compared with thermal and low-pressure chemical vapor deposition oxides. In addition, infrared spectroscopy was performed to characterize ECR oxide stoichiometry. The dependence of the Si-O and O-H content of these films will be described as a function of bias voltage applied to the substrate electrode.