CRITICAL DIMENSION MONITORING FROM LATENT IMAGE

摘要

A system for monitoring a latent image exposed in a photo resist (300, 310, 675, 790) during semiconductor manufacture is provided. The system includes one or more light sources (110, 635, 740), each light source (110, 635, 740) directing light (760, 1602, 1712, 1840, 1940, 2040) to the latent image and/or one or more gratings exposed on one or more portions of a wafer (160, 400, 540, 665, 910, 1204, 1820, 1920, 2020). Light reflected (770, 1604, 1714, 1842, 1942, 2042) from the latent image and/or the gratings is collected by a signature system (630, 720), which processes the collected light. Light passing through the latent image and/or gratings may similarly be collected by the signature system (630, 720), which processes the collected light. The collected light is analyzed and can be employed to generate feedback information to control the exposure. The collect light is further analyzed and can be employed to generate feed forward information that can be employed to control post exposure processes including development and baking processes.