REMOTE MICROWAVE PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION OF SIO2-FILMS - OXYGEN PLASMA DIAGNOSTIC

Silicon oxide is deposited by remote microwave plasma enhanced chemica l vapour deposition (RMPECVD). The silica films are produced by exciti ng oxygen in a microwave discharge while a mixture of 5% of silane dil uted in argon is introduced downstream. In the afterglow, double Langm uir probe measurements and rotational temperatures deduced from optica l emission spectroscopy (OES), show that the electron energy is transf erred to the gas when the pressure increases (19 - 26 Pa). Therefore t he electronic temperature decreases from 22000 to 11000 K and the gas temperature increases from 400 to 500 K. Moreover the microwave power (180 - 480 W) has an influence on the deposition rate and on the quali ty of SiO2 coatings (density and etch rate in an HF solution). This ef fect can be correlated with the increase in the electron density (0.7. 10(10) to 3.7.10(10) cm(-3)) and of the gas temperature (400 to 460 K) .