Impurity centers in silicon doped with rare-earth impurities of dysprosium, holmium, erbium, and ytterbium

The results of an investigation of the donor centers in Czochralski-grown s ilicon ion-implanted with rare-earth impurities of Dy, Ho, Er, and Yb are p resented. The formation of three groups of dominant donors with ionization energies less than 0.2 eV in silicon after annealing at 700 and 900 degrees C is discussed. The shallow donors at approximate to E-c-40 meV are interp reted as thermal donors containing oxygen and intrinsic defects. The two ot her groups of donor states are identified as centers containing rare-earth ions. (C) 1999 American Institute of Physics. [S1063-7826(99)00406-8].