METHOD TO FORM SUB-WAVELENGTH APERTURE FOR NEAR-FIELD OPTICAL SENSOR

摘要

PURPOSE: A forming method for a sub-wavelength aperture is provided to conveniently form the sub-wavelength aperture while improving reproducing property. CONSTITUTION: On an upper side of a silicon wafer(12), a silicon oxide film(14) and a silicon nitride film(16) are formed. The silicon nitride and the silicon oxide are dry etched to form an etching mask. A V-shaped groove(18) is wet etched on the silicon wafer by using the etching mask. A dry oxidizing process is performed, a sub-wavelength aperture(20) is formed at a vertex of the V-shaped groove in an ICP RIE(Inductively Coupled Plasma Reactive Ion Etching). Then, the silicon wafer at a lower surface is etched by using a KOH solution.