Low temperature pulsed etching of large glass substrates

Abstract

Glass plates of 20 cm diameter have been etched by SF₆ in a pulsed capacitively coupled 13.56 MHz discharge. The plates were mechanically clamped to the cooled substrate holder and allowed to heat due to ion bombardment. The average rf power was set at 220 W and the pulse frequency varied up to 200 kHz for duty cycles between 10% and 100%. For a pressure of 50 mTorr, pulse frequencies around 100 kHz and duty cycles below 30%, the etch rate was about double that of the continuous case and the glass plate temperature was between 90 and 100 °C about 30° below the continuous case. These results show that large plates of glass can be etched rapidly at 0.16 μm per minute at temperatures below the cross linking temperature of a photoresist mask. Show more