325-NM INTERFERENCE MICROSCOPE

We first discuss an interference microscope's 3D response in terms of Richards and Wolf's vector theory. We then report the results we obtai ned with a 325-nm interference microscope using an ultraviolet transpa rent beam splitter, short-working-distance Mirau interferometer. The m icroscope performs at near-ideal definitions with a measured FWHM of t he intensity spot at 0.14 mu m and a FWHM of the depth envelope intens ity at 0.25 mu m. Feasibility of a shorter wavelength system operating at 248 nm is demonstrated. (C) 1998 Optical Society of America.