Submicrometer-scale pattern generation via maskless digital photolithography

Maskless photolithography based on digital micromirror devices (DMDs) is considered the next-generation low-cost lithographic technology. However, DMD-based digital photolithography has been implemented only for micrometer-scale pattern generation, whereas sophisticated photonic devices require feature sizes of approximately 100 nm. In this study, we adopt a high-magnification objective lens ( 200 × ) for a custom-built digital photolithography system to generate submicrometer-scale patterns. We also improvise techniques to augment the digital photolithography, pattern tilting, and grayscale exposure. We demonstrate that photonic crystal band-edge lasers of various lattice structures and periods can be quality-assessment testbeds.