Large surface profile measurement with instantaneous phase-shifting interferometry

Abstract

Surface profile measurement of smooth surfaces is a vital area in many of today's industries, especially in wafer fabrication. The increased need for high-speed, noncontact online measurement with high accuracy and repeatability is of great interest for practical purposes. In this work, a modification of Michelson interferometers in combination with instantaneous phase-shifting interferometry is proposed for high-speed large flat-surface profiling. Experiments are carried out on a patterned wafer surface. The results obtained using this system are compared with a commercial profiler system to demonstrate the validity of the principle. © 2003 Society of Photo-Optical Instrumentation Engineers.