SURFACE SCANNING INSPECTION SYSTEM WITH INDEPENDENTLY ADJUSTABLE SCAN PITCH

摘要

A surface scanning wafer inspection system with independently adjustable scan pitch and associated methods of operation are presented. The scan pitch may be adjusted independently from an illumination area on the surface of a wafer. In some embodiments, scan pitch is adjusted while the illumination area remains constant. For example, defect sensitivity is adjusted by adjusting the rate of translation of a wafer relative to the rate of rotation of the wafer without additional optical adjustments. In some examples, the scan pitch is adjusted to achieve a desired defect sensitivity over an entire wafer. In other examples, the scan pitch is adjusted during wafer inspection to optimize defect sensitivity and throughput. In other examples, the scan pitch is adjusted to maximize defect sensitivity within the damage limit of a wafer under inspection.