Nonmonotonous distribution in the secondary defect depth in silicon ion-implanted layers

Two series of silicon samples were studied using the methods of transmission electron microscopy: 1 - samples prerendered amorphous by silicon (argon) ions and irradiated, afterwards, by boron ions and subjected to a two-stage annealing in nitrogen atmosphere (600 deg C - 1 h, 900 deg C - 10 min) ; 2 - samples irradiated sequentially by silicon (argon) ions, boron ions and arsenium ions (conditions and sequence of heat treatments are the same as in the first series). Three layers of secondary defects located in series at the depths down to 0.8 μm are found in the samples of the 1st series. Only a thin near-surface layer of secondary defects is found in the samples of the 2nd series. The results are explained by the peculiarities of the interaction of impurities with point defects in silicon used for implantation