Advanced wafer backside bevel characterization using a geometry measurement

Throughout high volume semiconductor manufacturing processing, many factors influence wafer defectivity, including the backside bevel shape of the wafer. This paper shows the relationship between the critical edge on the backside bevel of an incoming wafer and the specific defect level during manufacturing. A new methodology to characterize this critical backside bevel shape is presented. This characterization utilizes the PWG™ patterned wafer geometry metrology system and a known curvature metric (ZDD) [1]. The novelty of the methodology is the extension of the measurement radius closer to the wafer apex.