Low temperature pulsed etching of large glass substrates

The etch rate and the substrate temperature of a glass plate were studied for continuous and pulse rf discharges in a capacitive reactor with SF₆. Maximum etch rates were found for a pressure of 50 mTorr. For the continuous case, an etch rate proportional to the bias voltage was found for high powers above 700 W. The substrate measurements showed that the glass substrate can reach high temperatures and its final temperature agrees with that obtained using a simple radiation model. The etch rate and the substrate temperature were measured for pulse frequencies between 50 Hz and 200 kHz, for duty cycle between 10% and 50%.