Three-dimensional deep sub-wavelength defect detection using λ = 193 nm optical microscopy.
Optical microscopy is sensitive both to arrays of nanoscale features and to their imperfections. Optimizing scattered electromagnetic field intensities from deep sub-wavelength nanometer scale structures represents an important element of optical metrology. Current, well-established optical methods used to identify defects in semiconductor patterning are in jeopardy by upcoming sub-20 nm device dimensions. A novel volumetric analysis for processing focus-resolved images of defects is presented using simulated and experimental examples. This new method allows defects as narrow as (16 ± 2) nm (k = 1) to be revealed using 193 nm light with focus and illumination conditions optimized for three-dimensional data analysis. Quantitative metrics to compare two-dimensional and three-dimensional imaging indicate possible fourfold improvements in sensitivity using these methods.
Bryan M
BM
Barnes
Martin Y
MY
Sohn
Francois
F
Goasmat
Hui
H
Zhou
András E
AE
Vladár
Richard M
RM
Silver
Abraham
A
Arceo
D000465:Algorithms; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008422:Materials Testing / Q000379:methods*; D008853:Microscopy / Q000379:methods*; D053758:Nanoparticles / Q000648:ultrastructure*; D010363:Pattern Recognition, Automated / Q000379:methods*; D012680:Sensitivity and Specificity