Organometallic and coordinative photoresist materials for EUV lithography and related photolytic mechanisms

Sub-10 nm patterning with extreme ultraviolet (EUV) light is receiving immediate attention as a next-generation nanolithography technique, but photoresist materials optimized to EUV nanolithography are yet to come. While the absorption of EUV radiation by a photoresist can be enhanced by incorporating metal atom into organic molecule, the size of particle that undergoes photochemical crosslinking can be reduced to nano- and molecular-scales. Two different strategies have been reported to develop organometallic and coordinative EUV photoresists to date: metal nanoclusters and small-molecule photoresists. This review focuses on the strategies, describes structure–property relationship, and discusses related photolytic reaction mechanisms in photolithography. Overall, this review provides important insights into the design rules over organometallic and coordinative EUV photoresist materials, laying the groundwork for future developments in next-generation nanolithography photoresist and technologies.