The slot antenna microwave plasma source is used for remote plasma deposition of scratch resistant films on polycarbonate substrates. A grid separates the primary discharge from the process chamber. The monomer hexamethyldisiloxan is distributed 5-50 mm over the substrate positioned 5-25 cm from the separation grid. With argon in the primary discharge a good sticking interface polymer layer grows. An additional amount of oxygen leads to a quartzlike layer on top. Deposition rate is typically 0.5 mu m/min. Rubber and tumble abrasion tests are used to characterise the scratch resistance.