Novel CD measurement and precise pattern size extraction method for optical images

A new method for accurate CD measurement and precise pattern size extraction from optical images is proposed. The approach is based on the underlying field theory of optical image generation. The method demonstrates superior precision compared with traditional edge detection schemes based on the image and not on the field nature of image creation. The proposed method presents accuracy parallel to that achieved by SEM imaging. Therefore it provides an alternative to electronic microscopy measurements in certain cases. This new method may be implemented for applications of accurate mask-CD measurement, as well as for retrieving the mask model from an optical image for a die to model application.