As semiconductor devices have become more highly integrated and miniaturized, defects originating within single-crystal silicon occur more frequently. Defect observation of silicon wafer surfaces using atomic force microscopy (AFM) is an analysis technique that reduces defect density on silicon surfaces and, thereby, increases yield (Ref. 1). We have developed an AFM that can directly observe the entire surface of next-trend, 12-in. wafers. We observed the defects of 12-in. Czochralski (CZ) wafers and compared the results with those of 8-in. wafers. We also observed the defects of 12-in. epitaxial Si wafers as a reference. The defects of the 12- and 8-in. CZ wafers are similar, and the 12-in. wafers display two types of defects in the silicon crystals: (1) Crystal originated particle, which is a shape surrounded by a {111} facet, and (2) dislocation loops. These defects are caused when crystals are lifted, and reflect the lifting conditions (Ref. 2). Although, there were fewer defects on the epitaxial Si wafers than on the CZ wafers, defects like hillock were found on the epitaxial Si wafers.