200 keV ion implantation experiments in very high dose region

Nitrogen ions with an energy of 190 keV were implanted into the aluminum rich alloy (95% Al and 5% Mg) in the dose region from 2×10¹⁷ to 2×10¹⁹ ions/cm². The wurtzite type hcp AlN structure with a c-axis preferred orientation was formed. The nitrogen depth profile was Gaussian-like for low doses and the profile became trapezoidal with a flat-topped plateau almost equal to the stoichiometric ratio of AlN in the dose region more than 5×10¹⁷ ions/cm². For very high doses more than 8×10¹⁸ ions/cm², both the thickness of the AlN layer and the width ΔW of the nitrogen existence layer in front of AlN broadened as the dose increased. In case of dose 2×10 ¹⁹ ions/cm², the thickness was 1.2 μm and ΔW was 0.3 μm