Title :
Photolithographic Patterning in Supercritical Carbon Dioxide: Application to Patterned Light-emitting Devices
Author :
Hwang, Ha Soo ; Zakhidov, Alexander ; Lee, Jin-Kyun ; DeFranco, John A. ; Fong, Hon Hang ; Malliaras, George G. ; Ober, Christopher K.
Author_Institution :
Dept. of Mater. Sci. & Eng., Cornell Univ., Ithaca, NY
Abstract :
Photolithography is a high-throughput, cost-effective patterning technology. However, the application to organic electronic devices has been restricted because of its chemical compatibility issue with delicate organic materials. In this study we propose a new photolithography technique which utilizes supercritical carbon dioxide (scO2) as an organic electronic materials-benign development solvent. Supercritical carbon dioxide is a fluid that exists above its critical pressure and temperature (Pc=73.8 bar and Tc=31.1degC). Apart from the environmental advantages, useful process benefits result from the fact that most non-fluorinated organic materials are not damaged in contact with scCO2. A polymeric material composed of perfluorodecyl methacrylate (FDMA) and tert-butyl methacrylate (TBMA) was synthesized as a negative-tone photoresist, processible in scCO2. Micron-sized resist patterns on a Si wafer were successfully processed under i-line (lambda=365 nm) exposure conditions. The resist showed a capability to make patterns on the conductive poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS) film. The resulting resist pattern was finally applied to fabricate patterned polymer light-emitting devices.
Keywords :
organic light emitting diodes; chemical compatibility; micron-sized resist patterns; organic electronic materials-benign development solvent; organic materials; patterning technology; perfluorodecyl methacrylate; photolithographic patterning; photoresists; polymer light-emitting devices; polymeric material; supercritical carbon dioxide; tert-butyl methacrylate; Carbon dioxide; Chemical technology; Lithography; Organic chemicals; Organic electronics; Organic materials; Polymers; Resists; Solvents; Temperature; Additive patterning; Electroluminescence (EL); Photolithography; Subtractive patterning; Supercritical carbon dioxide (scCO2);
Conference_Titel :
Flexible Electronics and Displays Conference and Exhibition, 2008
Conference_Location :
Phoenix, AZ
Print_ISBN :
978-1-4244-2053-7
Electronic_ISBN :
978-1-4244-2054-4
DOI :
10.1109/FEDC.2008.4483878