Correct about HMDS. It will make things worse. Even your unexposed regions will suffer(and stick). For success with bare silicon processing, I use a 5 minute oxygen plasma RIE just prior to spin. The surface interface physics, and chemistry is different for nitrides, and in this case; the oxide you have. Hydrogen bonds. Being SiO2, piranha, followed by a rigorous bake is best. Which brings us to AP300 or Omnicoat. I suggest trying it. I have used Omnicoat with success on nitride, and oxide. The data sheet instructions are good. The important thing is to ensure that the correct Omnicoat bake temperature is indeed reached. Interesting side about Omicoat is the tensile stress it exhibited on quartz wafers. Stress: Carefully controlled by taking the longer bake ramping/process temp and cooling times throughout. Adhesion: Always err toward over-exposure for best results. Using a filter as recommended is great, do increase the dose by at least 40%. Interval is best for any films over 20 microns thick for most aligners. Developing: I use a two bath method. I use water to rinse, less stress inducing than IPA. Regards, and hope this helps. Brian C. Brian Czimback Nanobiotechnology Center Cleanroom Operations 350 Duffield Hall Cornell University Ithaca,NY 14853