Proportionality between ion-beam-induced epitaxial regrowth in silicon and nuclear energy deposition.

Abstract

Amorphous surface layers in silicon on sapphire have been epitaxially regrown with the use of ion beams. The amorphous layers, 1600 A\r{} thick, were formed by ion implantation of 2\ifmmode\times\else\texttimes\fi{}${10}^{15}$ $^{28}\mathrm{Si}^{+}$ ions/${\mathrm{cm}}^{2}$ of 80 keV energy at room temperature. The subsequent ion-beam-induced annealing was performed at a target temperature of 300 \ifmmode^\circ\else\textdegree\fi{}C with low-intensity beams of ${\mathrm{He}}^{+}$, ${\mathrm{N}}^{+}$, ${\mathrm{Ne}}^{+}$, ${\mathrm{Si}}^{+}$, ${\mathrm{Ar}}^{+}$, and ${\mathrm{Kr}}^{+}$ ions of 300 keV energy. Rutherford-backscattering and channeling technique with 315-keV protons was used for the analysis of the epitaxial regrowth. It is shown that the initial regrowth rate is proportional to the amount of energy deposited in elastic collisions by the annealing ions near the amorphous-crystalline interface. Support is given for a model in which migrating point defects arriving at the interface cause the epitaxial regrowth of the amorphous layer.