The specific features in the generation and motion of dislocations in Si single-crystal wafers after different heat treatments were investigated by the 4-point bending technique. It was demonstrated that annealing of Si single-crystal wafers at 450C led to substantial hardening as compared to the post-growth state. The O-containing precipitates and precipitate dislocation pile-ups formed in the Si wafer bulk during multi-stage heat treatment were efficient heterogeneous nucleation sites of dislocations under the action of thermal or mechanical stresses. It was found that the multistage heat treatment of the Si wafers under conditions providing the formation of an internal getter within their bulk results in considerable disordering of the wafer structure. The inference was made that the formation of the defect state in the crystal lattice of Si and the strength characteristics of Si wafers depended substantially upon the temperature–time schedules of the low-temperature stage of multi-stage heat treatment.

Specific Features in the Generation and Motion of Dislocations in Heat-Treated Silicon Wafers. M.V.Mezhennyĭ, M.G.Milvidskiĭ, V.F.Pavlov, V.Y.Reznik: Physics of the Solid State, 2002, 44[7], 1284-90