The effects of implantation dose and energy upon post-annealing defect formation in P-implanted material was studied by using etch pit studies and transmission electron microscopy. Previous work had shown that, following annealing, there were strong dose and energy dependences of the dislocation density which threaded to the surface. A super-linear increase in threading dislocation density, for implantation energies of between 180 and 1500keV was observed at a dose of 1014/cm2. There was a maximum in the threading dislocation density, at a dose of 1014/cm2, followed by a rapid decrease in threading dislocation density. Both the super-linear increase in threading dislocation density with increasing energy, and the rapid decrease with increasing dose, were investigated by means of transmission electron microscopic. Such a study of the higher doses revealed the formation of a strong bimodal loop distribution, with small loops averaging less than 100nm, and large loops averaging about 1μm in size. For doses ranging from 1014 to 5 x 1014/cm2, a super-linear decrease in threading dislocation density (from 106 to less than 104/cm2) coincided with a super-linear increase in small dislocation loops (from below 106 to above 1010/cm2). It was suggested that homogeneous nucleation theory could explain many of the results. However, the chemical properties of P also appeared to also play an important role in the formation of small dislocation loops and, perhaps, threading dislocations.

Threading Dislocation Evolution in Mega-Electron-Volt Phosphorus Implanted Silicon. C.Jasper, S.K.Banerjee, A.Hoover, K.S.Jones: Journal of Applied Physics, 2001, 89[8], 4326-31