Amorphization of ZnSe by ion implantation at low temperatures

Radioactive Cd and Se ions were implanted into high-resistivity ZnSe single crystals around 60 K and 300 K. Their lattice sites were determined by measuring the channeling and blocking effects of the emitted conversion electrons or positrons directly after implantation and after annealing at different temperatures up to 600 K. Implantation doses were in the range of 3×10 12 – 3×10 13 /cm 2 . The experimental results of this emission channeling technique yield a high substitutional fraction of the implanted ions directly after implantation at room temperature. At 60 K the substitutional fraction of implanted ions is highly sensitive on the ion dose. Above a critical dose of around 1.4×10 13 Cd/cm 2 or 2.1×10 13 Se/cm 2 the substitutional fraction completely disappears indicating an amorphous phase surrounding of the probe atom. Damage recovery was observed already below room temperature and at an annealing temperature around 500 K. A quantitative analysis of measured channeling yields will be given by comparison with calculated electron channeling profiles based on the dynamical theory of electron diffraction.