Edge-based optical proximity correction for near-field lithography

Near-field lithography can overcome the optical diffraction limit and achieve super-resolution by employing evanescent waves carrying fine information of the mask. However, the advanced inverse lithography technology-based optical proximity correction cannot be adopted to near-field lithography for enhancing exposure pattern fidelity. To solve this problem, this paper demonstrates an edge-based inverse lithography optical proximity correction approach for near-field lithography. After introducing the adjoint method, the edge gradient of the mask layout can be computed numerically. In combination with the gradient descent algorithm and the related edge segmentation, the edge-based inverse lithography optical proximity correction approach can be constructed for near-field lithography to clearly improve exposure pattern fidelity. Simulation results indicate that the exposure pattern deviation can be effectively suppressed because of mitigating the impact of optical proximity effects, and the finer segmentation of edges of mask layout would lead to better fidelity of exposure patterns. The proposed approach is expected to be applied to the near-field micro-/nano-fabrication field.