RMPECVD of silica films with a high microwave power (1600 W) parametric studies

In a large scale plasma reactor, a high microwave power of 1600 W is necess ary to obtain a homogeneous distribution of the plasma source. The increase of the microwave power allows to decrease the substrate temperature during the process (150 degreesC) with the formation of a dense silicon oxide lay er. In the range of variation of the parameters studied (pressure, temperat ure, R (oxygen flow rate / silane flow rate)) little variations of the film characteristics (density, etch rate, ...) are observed. However, the ERDA analysis shows that a low pressure (0.13 mbar) and a limitation of the depo sition rate (R = 160) allow to reduce the incorporation of impurities (H,C) in the oxide films. The FTIR spectra, systematically studied by the positi on, the full width at half-maximum and the area of the Si-O-Si band, enable to point out the composition and the morphology evolution of silicon oxide coatings and corroborate the previous results.