Formation of a layered structure in the distribution of boron atoms initiated in silicon by ion implantation
Myasnikov A. M., Obodnikov V. I., Seryapin V. G., Tishkovskii E. G., Fomin B. I., Cherepov E. I.
Secondary-ion mass spectrometry has been used to study the redistribution of boron isotopes in silicon samples subjected to diffusive doping with implanted boron to a total concentration ~2x 1020 cm~3 of the isotopes 10B and nB, followed by implantation of the isotope I0B+ at an energy of 180 keV in a dose of 1016 cm~2. Annealing at 900 °C gives rise to a quasiperiodic structure consisting of five clearly expressed peaks formed on the concentration profile of each isotope in the region subjected to ion implantation. The results are explained under the assumption that there is a decomposition of a supersaturated solid substitution solution of boron in silicon, initiated by an annealing out of structural defects built up during the bombardment. This process would be accompanied by the formation of precipitates containing boron with a defect-stimulated drainage of the free component of the boron to them.