Characterisation of residual disorder in Sn-implanted InP with perturbed angular correlation

InP substrates were implanted with ¹²⁰Sn, ¹¹⁵In and/or ³¹P ions and thereafter, with trace amounts of radioactive ¹¹¹In ions. Following rapid thermal annealling, the fraction of undisturbed ¹¹¹In sites was measured with perturbed angular correlation (PAC). Though Sn and In ions have comparable masses, undisturbed fractions of 42 and 67%, respectively, were experimentally determined as attributed to the charge on the ionised donor and differences in bond length. Precipitated Sn atoms were shown to have a negligible influence on the undisturbed fraction. Comparing In-, P- and In-and-P-implanted samples, excess P yielded a greater fraction of undisturbed sites relative to excess In (87 and 67%, respectively) as attributed to the lesser mass of P and hence, the lesser energy deposited in vacancy production. However, In-and-P-implanted samples yielded an intermediate value (81%), demonstrating the influence of non-stoichiometry. Also, complementary double-crystal X-ray diffraction measurements were in qualitative agreement with the results derived from PAC with the latter shown to be an effective analytical technique for the measurement of disorder in ion-implanted InP