Determination of the Temperature Coefficient of the Refractive Index of Liquids for Immersion Lithography

Abstract

The refractive indices of solids and liquids are of great importance in many areas of research. In order to find a preferable immersion fluid for integrated circuit(IC) production the refractive index and its variation with temperature at different wavelengths of distilled water and with other solutions such as 1.0 M magnesium chloride (MgCl2.2H20), 1.0 M sodium chloride (NaCl), 1.0 M sodium hydroxide (NaOH) and 1.0 M H2SO4 have been studied. A good immersion fluid should have a high refractive index and a lower temperature coefficient compared with water. MgCl2.2H2O was found to be the best solution having the highest refractive index and the lowest temperature coefficient of refractive index at different wavelengths of 578.00 nm 546.07 nm, 435.84 nm and 404.57 nm.