Enhancing re-detection efficacy of defects on blank wafers using stealth fiducial markers

摘要

To qualify tools of semiconductor manufacturing, particles unintentionally deposited in these tools are characterized using blank wafers. With fast optical inspection tools one can quickly localize these particle defects. An example is TNO's Rapid Nano, which operates in optical dark field. The next step is defect review for further defect characterization. When the blank wafers are transferred to another tool, e.g. a SEM or an AFM the absolute defect position information is lost. Therefore, the re-detection of the defects in the review tool is time consuming. To enhance the re-detection speed, a fiducial marker system can be used that couples the coordinates of the fast inspection tool to the coordinates of the characterization (review) tool.