J. Phys. IV France 02 (1991) C2-421-C2-428
DOWNSTREAM MICROWAVE PLASMA ENHANCED CHEMICAL VAPOUR DEPOSITION OF SiO2 USING O2/SiH4 AND N2O/SiH4 MIXTURESH. DEL PUPPO1, T. SINDZINGRE2, L. PECCOUD2 and J. DESMAISON1
1 Laboratoire de Céramiques Nouvelles, URA CNRS 320, F-87060 Limoges cedex, France
2 D. LETI/IRDI, CEA, CENG, 85X, F-38041 Grenoble cedex, France
The deposition of silicon dioxide by downstream microwave plasma-enhanced chemical vapor deposition (PECVD) has been investigated. A comparative study of the properties of oxide layers deposited at a pressure of 200 mtorr with two different oxidizing gases (N2O or O2) is reported. Particular emphasis is given to the influence of the substrate temperature and reactive gas ratio R = oxidant flow/silane flow on the deposition rate, mechanical stress, refractive index and etch rate. The results show that the properties of silicon oxide films are dependent on temperature below 400°C. But for this temperature and a gas ratio R=1, films are roughly equivalent and independent of the nature of the oxidizing gas used. Indeed they exhibit similar refractive index (≈ 1,47), etch rate (≈ x 3 current thermal oxide), 2.109 dynes/cm2 tensile stress, Si-H and Si-OH bonding present in infrared spectra. Nevertheless, the growth rates are very different for O2 and N2O, 5 um/min and 1,5 um/min respectively, but significantly higher that those commonly achieved with classical PECVD methods. Moreover, it is shown that under appropriate process variable conditions, the deposited films are suitable for dielectric passivation applications.
© EDP Sciences 1991