ELECTRICALLY ACTIVE, ION-IMPLANTED BORON AT THE SOLUBILITY LIMIT IN SILICON

For 30 keV B implants in Si, doses above 1.5 X 10(14) B/cm2 will lead to dislocation formation during a subsequent 900-degrees-C anneal to m ake the B electrically active. Although dislocations are avoided for d oses < 1.5 x 10(14) B/cm, the B concentration is only approximately 1 X 10(19) B/cm3, a factor of 4-5 lower than the solid solubility of B i n Si at 900-degrees-C. Using multiple implant/anneal steps, we demonst rate here that implanted, electrically active B can be introduced up t o the solid solubility limit while avoiding dislocation formation.