Could you have another dielectric layer above the PMMA. Is there any reason you are using PMMA? -----Original Message----- From: Emanuele Orabona [mailto:emanuele.orabona@na.imm.cnr.it] Sent: Saturday, 6 March 2010 8:20 AM To: General MEMS discussion Subject: [mems-talk] PMMA as gate insulator Dear all, I tried to realize an OTFT using PMMA as gate insulator and PEDOT/PSS as electrodes. In the top gate structure the PEDOT/PSS penetrated in the PMMA layer creating short circuit with source and drain. I think that PMMA layer is porous. I've also tried to change solvents, temperatures, deposition conditions, deposition techniques. How can i solve this problem? Thank you Emanuele