POLARIZATION MONITORING RETICLE DESIGN FOR HIGH NUMERICAL APERTURE LITHOGRAPHY SYSTEMS

摘要

This invention relates to the manufacture of semiconductor substrates such as wafers and to a method for monitoring the state of polarization incident on a photomask in projection printing using a specially designed polarization monitoring reticle for high numerical aperture lithographic scanners. The reticle measures 25 locations across the slit and is designed for numerical apertures above 0.85. The monitors provide a large polarization dependent signal which is more sensitive to polarization. A double exposure method is also provided using two reticles where the first reticle contains the polarization monitors, clear field reference regions and low dose alignment marks. The second reticle contains the standard alignment marks and labels. For a single exposure method, a tri-PSF low dose alignment mark is used. The reticles also provide for electromagnetic bias wherein each edge is biased depending on that edge's etch depth.