Innovative wafer defect inspection mode: self-adaptive pattern to pattern inspection

This study introduces a novel self-adaptive Pattern-to-Pattern (P2P) inspection mode for wafer defect inspection. Different from the traditional Die-to-Die (D2D), Cell-to-Cell (C2C), and Die-to-Database (D2DB) inspection modes, the newly proposed P2P inspection mode has the advantages of no restriction on the inspection region and low dependence on image quality. It works with both SEM images and optical images from different inspection equipment. Using the design layout information, the inspection images are aligned with the design and divided into basic component patterns according to the geometric features of the design pattern. These components are then analyzed through similar pattern comparison to enable the inspection of unique and complex patterns. This self-adaptive method eliminates the influence of the manufacturing process variations by comparing aligned similar image patterns, thereby preventing the reporting of defects highly dependent on the inspection algorithm settings. To facilitate further analysis, a database of the basic pattern components is created by collecting extensive images along with corresponding design layout information.