Properties of the TiSi2/p+n structures formed by ion implantation through silicide and rapid thermal annealing

Silicided p+n junctions and contact resistivity test structures were formed by implantation of BF2 through TiSi2 in crystalline as well as in Si+ or Ge+ preamorphized silicon. A subsequent rapid thermal annealing at 950 °C in nitrogen atmosphere was performed to activate the dopant, to remove the ion implantation damage, to increase the silicide conductivity, and to improve the electrical characteristics of the junction. Very low leakage currents and low contact resistivities were measured on samples without preamorphization. With Si+ or Ge+ implantation the channeling of boron was suppressed but residual defects below the original amorphous-crystalline (a-c) interface gave rise to an increased leakage current. A Ti-related defect level was found by deep level transient spectroscopy in the silicon substrate up to a depth of some micrometers.