Defect structure of tin-doped inas single crystals grown by the Czochralski method

Indium arsenide (InAs) single crystals heavily doped with Sn are found to have various violations of structural perfection, which depend on the Sn concentration in different regions of crystal. At low charge-carrier (electron) concentrations (~1.5 × 10¹⁸ cm^–3) an unusual annular distribution of dislocations in the cross section is observed for the initial parts of crystal. The dislocation density lies in the range of (0.1–1.0) × 10⁴ cm^–2. At a carrier concentration above 4.0 × 10¹⁸ cm^–3 indium inclusions and “vicinal growth hillocks” are observed in the final parts of crystals. The dislocation density in the final cross sections of crystals, in which the aforementioned defects are not observed, is in the range of (0.4–2.1) × 10⁴ cm^–2.