Template-Set Approach to VLSI (Very Large Scale Integrated) Pattern Inspection

摘要

A new approach is described for the automatic detection of defects in VLSI circuit patterns such as photomasks and wafers. It is based on morphological feature extraction using templates that represent a set of local pixel configurations within a specified window. These templates are stored in content-addressable memories (CAMs) to facilitate parallel comparisons of window-pattern scanning over a tested image. Maskable CAMs reduce the size of a template set substantially. Two error-detection algorithms are implemented to detect both random defects and dimensional errors.