Vacuum-free photolithographic patterning of conducting polymer film

Understanding the relationship between a certain organic material and the corresponding orthogonal solvent improves the realistic possibility of photolithographic patterning during the fabrication of organic devices. However, an all-solution-based patterning process has not been established because the dry-etching process used for micropatterning must be performed in a vacuum chamber, which is not appropriate for a printing process and results in a low throughput of products at the industrial level. Here, we demonstrate a vacuum-free patterning method using conventional photolithography. It is a main breakthrough in that it washes away the etchant by blowing with air in a very short time. This short-term air-blowing process dramatically reduces the undercut below the photoresist. As a result, mask patterns of nearly the same size could be transferred onto an organic object. Compared with ordinary wet etching process, the undercut is reduced to the 1-micrometer scale, allowing the realisation of a fine pattern size. The process developed here will enhance the throughput of manufacturing systems using an all-solution-based process.