Positron annihilation and Hall-effect/resistivity experiments were used to identify and quantify vacancy-impurity complexes formed in molecular-beam epitaxially grown Si at very high As doping levels greater than 1020/cm3. The results indicated that V-As3 was the dominant vacancy defect which exists at concentrations relevant to the electrical deactivation of doping. Larger complexes, tentatively identified as V2-As5, were also present at high concentrations. The V-As3 and V2-As5 defects were removed by annealing at 800 and 900C, respectively. The rapid thermal annealing led to lowest concentrations of these deactivating defects, indicating that their formation was limited by migration processes during the cooling down.

Electrical Deactivation by Vacancy-Impurity Complexes in Highly As-Doped Si. V.Ranki, K.Saarinen, J.Fage-Pedersen, J.Lundsgaard Hansen, A.Nylandsted Larsen: Physical Review B, 2003, 67[4], 041201 (4pp)