For efficient yield prediction and inductive fault analysis of integrated circuits

it is usually assumed that defects related to the photolithographic in the wafer surface have the shape of circular discs

ellipse or squares.Real defects

however

exhibit a great variety of different shapes

their shapes usually play an extremely important role in the yield prediction.The fractal characterizations of real defect outlines are discussed

and the fractal dimension is estimated by wavelet transform

the result is in agree with the actual feature.So it provides new feature parameters for the characterization and computer simulation of defect outline.