Sub-50 nm patterning of alloy thin films via nanophase separation for hydrogen gas sensing

A novel patterning method achieves two-dimensional nano-patterning of metal nanofibers by depositing a platinum-cerium alloy film on a silicon wafer and inducing phase separation in an oxygen-carbon monoxide atmosphere. The resulting nano-patterned thin film, Pt#CeO₂/Si, consists of platinum and cerium oxide with an average pattern width of 50 nm and exhibits potential as a hydrogen sensor with sensitive electrical responses to hydrogen ad/desorption. The patterning method introduced herein addresses the challenge of wavelength limitations in traditional optical lithography, offering a scalable approach for sub-50 nm patterns, which are crucial for advanced sensor and electronic applications.