Measurement of silicon wafer rougness by atomic force microscopy: An interlaboratory comparison

摘要

We have compared silicon wafer roughness values measured by four laboratories using atomic force microscopy. An atomically-stepped epitaxial (111) wafer allowed validation of height calibrations, and also proved valuable for diagnosing tip quality and noise. Initial roughness values from a highly polished wafer (<0.1 nm rms) spanned a range of a factor of two, but after taking tip quality, periodic noise, and artefactual image curvature (present in larger area scans) into account, this account, this range reduced to +-(20-25)percent. In the case of a prepolished wafer (> 1nm rms), the variation in roughness values appeared to reflect the surface roughness statistics.