An x‐ray step‐scanning topographic technique combined with an automatic Bragg‐angle control (ABAC) system has been developed and applied to the study of crystal perfection of silicon wafers subjected to copper decoration, phosphorus diffusion, and thermal oxidation. This technique has revealed exact spatial configurations of individual lattice imperfections such as swirl defects, diffusion‐induced dislocations, oxidation‐induced stacking faults, and precipitates.