Dear all, I am currently trying to alter the surface properties of pyrex wafers from hydrophilic to hydrophobic (contact angle > 100°). I need to coat one side of the wafer and structure the layer either by RIE or a lift-off process using photoresist as a sacrificial layer. I already tried to deposit teflon-like layers from c4f8 in a DRIE-tool. But these layers will not stick to the pyrex after lift-off in acetone and rinsing in water. Same with HMDS, deposited from the gas phase at 140°C. The c4f8-plasma deposited layers adhere perfectly to silicon by the way. Does anybody have experience with depositing and structuring teflon-like layers on pyrex or can anybody suggest any adhesion promoter or surface treatment of the pyrex to increase the adhesion of the hydrophobic coating? Thanks for your help, Marco