The annealing behavior of antimony implanted polycrystalline silicon

Abstract

Dopant redistribution and sheet resistance of polycrystalline silicon films implanted with 100-keV Sb+ ions to a dose of 1×1015 cm−2 or 3×1015 cm−2 have been investigated as a function of different annealing conditions. The correlation between Sb depth profiles, as measured by Rutherford backscattering, and sheet resistance provides considerable insight into the Sb doping behavior. In particular, low-temperature (∼600 °C) short-time (0.5 h) anneals resulted in good dopant activation without redistribution of the implanted Sb, whereas higher-temperature anneals (≳900 °C) resulted in considerable redistribution. The sheet resistance of the films appeared to be controlled, to a large extent, by dopant segregation at grain boundaries and the fraction of the redistributed Sb within the grains.