Depth profiles of Fe and Cr implants in InP after annealing

Abstract

The post-annealing concentration profiles of Fe and Cr implants in undoped InP substrates are studied by secondary ion mass spectrometry. Annealing temperatures range from 550 to 750 °C. Iron and chromium show similar behavior; the profiles are divided in three regions: the near surface zone where metals pile up, the zone in front of the projected range (Rp), around 0.8 Rp, where Fe and Cr atoms are trapped by residual damage, and a region around Rp+ΔRp, where a well-defined peak, with maximum concentration reaching 3–4×1018 cm−3, is observed. On each side of that peak, solute atoms are depleted down to the limit solubility: 1×1017 cm−3 for iron, 2×1016 cm−3 for chromium. The results are interpreted according to the calculations of L. A. Christel et al. [J. Appl. Phys. 52, 5050 (1981)] on stoichiometric disturbances in ion-implanted compound semiconductors.