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Lattice damage in single crystals of Cu after self-implantation studied by channeling

1986; Elsevier BV; Volume: 15; Issue: 1-6 Linguagem: Inglês

10.1016/0168-583x(86)90315-0

1872-9584

M. Vos, D.O. Boerma,

Nuclear materials and radiation effects

The dependence of the range of the damage on the temperature and the orientation of the crystal during implantation was studied. Single crystals of copper were implanted at RT with a dose of 2 × 1016/cm2 Cu ions at an energy of 110 keV. The maximum depth of the damage after implantation along a crystal axis is much larger than the maximum depth after off-axis implantation. The decrease of the damage range from 500 to 150 nm with increasing angles with the crystal axis continues until 20° out of the string. Implantation at 77 K causes an increase of the damage level but hardly any difference in the range of the damage. In all these experiments the range of the damage can be explained qualitatively by channeling of a fraction of the implanted Cu ions. However, implantation at a temperature of 625 K changes the damage profile completely. The first 300 nm are almost damage-free and the main damage is at a depth between 400 and 1500 nm. The level of the damage after high temperature implantation is always lower than the damage level after room temperature implantation. It is explained that after implantation at room temperature and below, almost all interstitials recombine with (clusters of) vacancies. However, after implantation at temperatures above 550 K a flux of both interstitials and vacancies migrate into the crystal. It is concluded that after high temperature implantation the damage is caused by migrating defects.