ELLIPSOMETRIC SCATTEROMETRY FOR THE METROLOGY OF SUB-0.1-MU-M-LINEWIDTH STRUCTURES

We describe a modification to our existing scatterometry technique for extracting the relative phase and amplitude of the electric field dif fracted from a grating. This modification represents a novel combinati on of aspects of ellipsometry and scatterometry to provide improved se nsitivity to small variations in the linewidth of subwavelength gratin gs compared with conventional scatterometer measurements. We present p reliminary theoretical and experimental results that illustrate the po ssibility of the ellipsometric scatterometry technique providing a met rology tool for characterizing sub-0.1-mu m-linewidth. (C) 1998 Optica l Society of America.