Enhanced corner sharpness in DMD-based scanning maskless lithography using optical proximity correction and genetic algorithm

An optical proximity correction (OPC) method is proposed to enhance the UV patterning quality in a DMD-based scanning-type maskless lithography system with an oblique scanning and step-strobe lighting (OS 3 L) scheme. The system setup, software programming, and image processing procedures are detailed. A simulation model is also introduced to predict the patterning results for a given DMD mask. Utilizing this model, a genetic algorithm (GA) is developed to optimize the mask pattern for OPC. The GA-OPC method reduces the corner-rounding effect in metal patterns fabricated using digital maskless lithography and metal lift-off processes. Optical images of the metal patterns show that the proposed GA-OPC method effectively mitigates the corner-rounding effect and improves the patterning fidelity. The work presented in this study lays the foundation for further enhancing the patterning capabilities and quality of DMD-based maskless lithography.