A Detection Method for a T-Topped Profile in Resist Patterns by Top-Down-View Critical Dimension Scanning Electron Microscope

A new detection method for a T-topped profile in resist patterns is proposed. This method can determine a T-topped tendency from only a single top-down critical dimension scanning electron microscope (CD-SEM) image. The method is based on the relationship between a cross-sectional pattern profile and a shape of a bright area near the pattern edge in the top-down image. Two kinds of indices for a T-topped tendency are obtained from line-edge roughness, width of the area and a correlation coefficient between the left and right borders of the area. Both indices agreed well with actual cross-sectional profiles of various resist patterns.