Comparison of metrology methods for quantifying the line edge roughness of patterned features

Comparisons are made of two atomic force microscopes in different modes of operation, and two scanning electron microscopes, one high and one lower resolution for quantifying the edge roughness of patterned features in resist and silicon. Definitions of the edge roughness magnitude and spatial frequency are given. For each metrology method, the parameters that limit the edge roughness measurement and how they compare to the parameters that limit the critical dimension measurement are addressed. An attempt to quantify the edge roughness spatial frequency is also discussed. For the two best metrology methods the repeatability of the measurements was determined, and measurements were made to understand the correlation between them. (C) 1999 American Vacuum Society. [S0734-211X(99)02306-9].