Abstract
GaAs crystals and Al~0.43~Ga~0.57~As epitaxial layers of low dislocation density were implanted with 146 keV, 100 keV and 60 keV H^+^ ions and studied by recording of rocking curves, reciprocal space mapping and Braggβtype section topography. The Xβray investigation were performed also in the case of GaAs double implanted with 146 keV and 60 keV protons with doses of 6 Γ 10^15^ cm^β2^ and 4.2 Γ 10^15^ cm^β2^, with penetration ranges differing by a factor 2. The rocking curves and Braggβtype section patterns for single implantation were readily explainable by approximating the strain profiles by the pointβdefect distribution calculated with the TRIM95 program. In the case of double implantation with hydrogen ions the rocking curve contained much narrower interference maxima than the curves for single implantation. The experimental curve was well approximated by the theoretical one obtained by numerical integration of the TakagiβTaupin equations. The strain profile in this calculation was a sum of strain profiles of single implantations. The narrow interference maxima were most probably caused by beating of the radiation, reflected by two strain maxima located at different depths in the implanted crystal. (Β© 2006 WILEYβVCH Verlag GmbH & Co. KGaA, Weinheim)