REMOTE AND DIRECT MICROWAVE PLASMA DEPOSITION OF HMDSO FILMS - COMPARATIVE-STUDY

Direct plasma polymerization (DPP) and remote plasma polymerization (RPP) for deposition of scratch-resistant films on polycarbonate substrates are compared. A slot antenna microwave plasma source (SLAN I) was applied for plasma generation. Argon and oxygen as carrier gases and hexamethyldisiloxane (HMDSO) as a monomer were used. Variation of the oxygen-to-HMDSO ratio for RPP allows a smooth transition between polymeric and quartz-like layers of the film. Deposition rates of 2.5 mu M min(-1) for DPP and 0.5 mu m min(-1) for RPP are typical. The substrate thermal load limits th e microwave power for the DPP to below 1.2 kW. No such limitation was found for the RPP. Good films are achieved for distances from the edge of the slot antenna of less than 20 mm for DPP and up to 25 cm for RPP. RPP allows organic deposits on the plasma chamber walls to be avoided. Typical pressure, oxygen dow and HMDSO flow are 0.8 mbar, 200 seem and 25 seem respectively.