Fabrication of silicon nanobump arrays by near-field enhanced laser irradiation

Abstract

A simple approach to fabricate two-dimensional nanobump arrays on silicon (Si) substrate is reported. In the process, a single 248 nm excimer laser pulse was applied on a self-assembled monolayer of 1.5-μm-diameter silica microspheres on a n-doped (100) Si wafer. After laser irradiation at a fluence of 300 mJ/cm2, a regular array of conical Si nanobumps surrounded by a ring shaped trench were fabricated. The structure of the nanobump arrays was characterized by scanning electron microscope, and atomic force microscope. The formed nanobumps were determined to be Si-based bumps with energy disperse spectroscopy. The mechanisms involved in the formation of nanobumps were discussed.