Patent ID: 6956658
Filing Date: 2005-10-18
Classification: G01B,G01N

Abstract:
1. A method for measuring at least one of an erosion and dishing on a semiconductor wafer, comprising the steps of: transmitting a first light signal toward the semiconductor wafer; receiving a reflected light signal that has reflected off said semiconductor wafer, said reflected light signal comprising a first mixed reflected polarized component having a first phase and a second mixed reflected polarized component having a different phase; separating from said reflected light signal said first mixed reflected polarized light signal component having a first phase and said second mixed reflected polarized light signal component having a different phase, wherein said first mixed reflected polarized light signal component comprises both P-polarized and S-polarized light relative to the plane of incidence of said reflected light signal, and wherein said second mixed reflected polarized light signal component comprises both P-polarized and S-polarized light relative to the plane of incidence of said reflected light signal; detecting a first intensity of said first mixed reflected polarized light signal component; detecting a second intensity of said second mixed reflected polarized light signal component; determining a difference in phase between said first and second mixed reflected polarized light signal components based upon said first and second intensities; and measuring at least one of erosion and dishing based upon said difference in phase.