Photoresist-derived porous carbon for on-chip micro-supercapacitors

Photoresist, which is frequently used in existing microelectronics processing, can be pyrolyzed to form a conductive carbon film. We demonstrate that a pyrolysis technique of SPR-220 photoresist, consisting of heating in Ar ambient to 900 °C followed by further annealing in an H2/Ar mixture, results in a high surface area porous carbon, applicable to supercapacitor electrode fabrication. Electrochemical testing of the pyrolyzed photoresist film yields a specific areal capacitance of 1.5-3.5 mF/cm2 and a specific volumetric capacitance of 15-35 F/cm3. These results are obtained on the as-pyrolyzed films, without additional activation or deposition of electroactive species. The cycling stability of the films is shown to be robust over 10,000 cycles. This photoresist pyrolysis process could be readily integrated into microelectromechanical systems or microelectronics technology for on-chip energy storage.