Influence of damage depth profile on the characteristics of shallow p+/n implanted junctions

Shallow p+/n junctions are produced by 10 keV boron implantation into self-ion preamorphized silicon and furnace annealing in the temperature range 600 to 1000 0C for 30 min. The electrical characteristics of the junction improve with increasing temperature, the strongest reverse current density I/sub R/ decrease occurring between 700 and 800 0C. This diode behaviour is correlated with the profiles of the residual lattice strain, determined by double crystal X-ray diffraction on samples implanted with silicon ions. It is shown that interstitial clusters, characterizing the tail of implantation damage and surviving for T <= 700 0C; are much more effective on I/sub R/ than the commonly observed dislocation loops. The disappearance of the clusters at 800 0C is closely related to the sharp drop in I/sub R/ at the same temperature. On the contrary, the dislocation loops, responsible for the lattice strain observed up to 900 0C, have a moderate influence on I/sub R/ and only when located in the space charge region. (author)