Numerical simulation research of catenary tip-insulator-metal structure for nano-lithography.

Catenary optics has attracted much interest due to its unique properties in wave-front manipulation, field enhancement, and dispersion engineering. In this paper, the applications of catenary optics in the near-field lithography are studied. The catenary shaped nanostructures and tip-insulator-metal (TIM) structures are simultaneously utilized to increase the contrast ratio of the focal plane and to give rise to a sharp focusing focal spot with high intensity. Moreover, the full width at half-maximum of the focal spot maintains well below the diffraction limit. The proposed catenary TIM structure may improve the quality of near-field lithography and find applications in super-resolution near-field direct writing nano-lithography.