Characterizing resists and films with VUV spectroscopic ellipsometry

摘要

Spectroscopic ellipsometry has been the technique of choice to characterize thin films and multilayers in semiconductor manufacturing. Extending this technology into the vacuum ultraviolet range, down to 140nm, however, for emerging 157nm optical lithography applications, requires an environment that avoids the absorbing effects of oxygen and water vapor below the 190nm wavelength; these must be reduced to the parts/million range. In addition, the optical setup for VUV spectroscopic ellipsometry must put the monochromator in the ellip-someter's polarizer arm to avoid photobleaching, and the ellipsometer must work in a rotating analyzer configuration to minimize parasitic polarizations.