Non-Contact NSOM Lithography for 2D Photonic Structure Fabrication

We demonstrate the near-field scanning optical microscope (NSOM) lithography in the non-contact mode as an effective optical method for fabrication of the two-dimensional (2D) submicrometer structures in photoresist layer. The patterning of the structures using NSOM is done through a direct writing process, which is performed by the optical near-field produced at the tip of a fiber probe. We employ the non-contact NSOM lithography using a metal coated fiber tip with submicrometer aperture in combination with 3D nanoposition piezosystem working in two modes. Such prepared 2D structures in thin photoresist layer on the GaAs substrate have either a typical hole array character or any desired 2D arrangement. By the optical and scanning probe diagnostics, the submicrometer hole diameter is demonstrated.