DEVICE AND METHOD FOR OPTICAL INSPECTION OF SEMICONDUCTOR WAFER

摘要

A wafer measurement station (19) integrated within a process tool (11) has a scatterometry instrument (35) for measuring patterned features on wafers (31). A wafer handler (17) feeds wafers between a cassette (15) and one or more process stations (13) of the process tool. Wafers presented to the measurement station are held on a wafer support (33), which may be moveable, and a scatterometry instrument has an optical measurement system (41) that is moveable by a stage (39) over the wafer support. A window (37) isolates the moveable optics from the wafer. The optical measurement system are microscope-based optics forming a low NA system. The illumination spot size at the wafer is larger than a periodicity of the patterned features, and data processing uses a scattering model to analyze the optical signature of the collected light.