Oxygen and Erbium related donor centers in Czochralski grown silicon implanted with erbium

The Hall effect measurements were conducted on Czochralski-grown silicon after implantation of erbium and two-step annealing at 700 °C and 900 °C. After the first step the formation of oxygen-related shallow donors was observed at Ec in the range 20–40 meV and erbium-related donor centers at ≈Ec-70 meV and ≈Ec-120 meV. Along with the same oxygen-related shallow thermal donors and donor centers at ≈Ec-70 meV, other donor centers at ≈Ec-150 meV are formed following the 900°C anneal, instead of those at ≈Ec-120 meV. The new donor states are of particular interest because of their possible involvement in the photoluminescence process. The obtained results for erbium-implanted silicon are compared with some fragmentary DLTS data found in the current literature on the donors with ionization energies less than 0.2 eV.