Metrology of optically-unresolved features using interferometric surface profiling and RCWA modeling.
Rigorous coupled wave analysis (RCWA) interprets 3D white-light interference microscopy profiles and reveals the dimensions of optically-unresolved surface features. Measurements of silicon etch depth of a 450-nm pitch grating structure correlate to atomic force microscopy with R(2)= 0.995 and a repeatability of 0.11nm. This same technique achieves a <1nm sensitivity to 80-nm lateral widths of 190-nm pitch gratings using a 570-nm mean wavelength.
de Groot
Peter
P
Zygo Corporation, Laurel Brook Road, Middlefield, CT 06457, USA. peterd@zygo.com
Colonna de Lega
Xavier
X
Liesener
Jan
J
Darwin
Michael
M
D003198:Computer Simulation; D007368:Interferometry / Q000379:methods*; D008422:Materials Testing / Q000379:methods*; D008853:Microscopy / Q000379:methods*; D008962:Models, Theoretical; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity