Kei Sakai

Line edge roughness measurement technique for fingerprint pattern in block copolymer thin film

Fingerprint edge roughness (FER) is proposed to characterize high frequency roughness of fingerprint pattern edges assembled by lamella forming block copolymer (BCP). The FER is a roughness index which does not include the roughness component of the fingerprint curvature. A technique to evaluate FER by using CD-SEM is also proposed. Centerline of the fingerprint patterns were extracted by utilizing binarization and slimming algorithm, and line width, line width roughness and line edge roughness along the centerline were measured. The FER thus measured showed a good agreement with those determined by utilizing conventional line edge roughness analyzing algorithm. The FERs of fingerprint patterns assembled with various BCP formulations were analyzed. As a result, the proposed technique successfully detected the line edge roughness difference between each BCP formulations with different compositions. The results indicate that the FER might be a useful index to evaluate the patterning performance of BCP as a material for DSA process. The proposed technique will provide a method for fast and easy development of BCP materials and processes