Investigations on ‘doping stacking fault’ pyramids

So-called ‘doping stacking fault’ pyramids discovered in Sb-doped Czochralski pulled silicon single crystals have been shown to be invisible in the electron microscope and in X-ray topography. Several hypotheses were examined in order to find an explanation for the nature of the faults. The idea that planes of foreign atoms (Sb) might be built into the crystal, or that a single-plane stacking fault (with $\text{R}\text{= ?}\text{1}\text{4}\text{[111]}$) might be present had to be abandoned. The assumption of intrinsic/extrinsic stacking fault pairs composing the pyramids appears to be most likely. The possibility of the occurance of doping stacking faults together with ‘normal’ stacking fault pyramids in epitaxial wafers is discussed.