An offline roughness evaluation software and its application in quantitative calculation of wiggling based on low frequency Power Spectral Density method

It is greatly important to accurately characterize the critical dimension (CD) and the roughness of line patterns in advanced lithography and etch process. Thus we wrote an offline roughness evaluation software and did lots of relevant researches. Two different edge finding algorithms are compared to reduce the CD uniformity. Power Spectral Density (PSD) algorithm is used to analyze the LER and LWR. Palasantzas function is used for fitting the PSD data and giving three important parameters. Such software could evaluate the line wiggling in practical applications. The origin of line wiggling and qualitative methods based on low frequency PSD is studied. With the help of the models and algorithms, we can figure out the existence and strength of wiggling for a SEM image.