Electron‐microscope photographs of a germanium single crystal surface subjected to prolonged argon‐ion bombardment under conditions used for surface cleaning disclosed etch patterns of a type completely different from those observed after chemical etching alone. The dimensions and distribution of the bombardment‐induced pits were such that the patterns were not detectable either with an optical microscope or by low‐energy electron diffraction. Approximately 95% of the surface remained undamaged. Bombardment of silicon and germanium at 500 ev for prolonged periods at higher current densities produced a different type of etching which may be associated with screw‐type dislocations.