Fabrication of grating structures on silicon carbide by femtosecond laser irradiation and wet etching

Abstract

A method for fabricating deep grating structures on a silicon carbide (SiC) surface by a femtosecond laser and chemical-selective etching is developed. Periodic lines corresponding to laser-induced structure change (LISC) are formed by femtosecond laser irradiation, and then the SiC material in the LISC zone is removed by a mixed solution of hydrofluoric acid and nitric acid to form grating grooves. Grating grooves with a high-aspect ratio of approximately 25 are obtained. To obtain a small grating period, femtosecond laser exposure through a phase mask was used to fabricate grating structures with a 1.07 μm period on the surface of the SiC.