LINNIK MICROSCOPE IMAGING OF INTEGRATED-CIRCUIT STRUCTURES

Experimental one-dimensional intensity and phase images of thick (>200 nm) oxide lines on silicon are presented together with profiles predi cted from the waveguide model. Experimental results were obtained with a purpose-built Linnik interference microscope that makes use of phas e-shifting interferometry for interferogram analysis. Profiles have be en obtained for both TE and TM polarizations for a wide range of focal positions and in both bright-field [type 1(a)] scanning and confocal modes of microscope operation. The results show extremely good agreeme nt despite several simplifying assumptions incorporated into the theor etical model to reduce computing times. (C) 1996 Optical Society of Am erica