Determination of refractive indexes of dielectric films by the use of immersion liquids

Abstract

AbstractExamples of using immersion liquids in ellilipsometry and multiple‐beam interferometry are given. The refractive index of very thin (∼ 5.0 nm) silica films on silicon and on films of silicon nitride are determined by the ellipsometry method. The method of precise determination of refractive index of monolayer dielectric films is described when a precision equal to ± 3 · 10−4 was reached. A method of determination film thicknesses near the substrate surface in a twolayer system is suggested. The construction of different prisms is given by means of which the immersion liquids are inserted. The selection of the equations for the determination of refractive index in the multiple‐beam interferometry is discussed. Two versions of the use of immersion liquids for the determination of refractive indexes of dielectric films by interferometry method are given.