AVOIDING PREAMORPHIZATION DAMAGE IN MEV HEAVY ION-IMPLANTED SILICON

Implantation of 1.0 MeV In-115 in Si results in secondary-defect formation during subsequent 900-degrees-C annealing if the total number of displaced Si atoms is greater than 1.6 X 10(17)/cm2, achieved with a dose near 1.5 X 10(13)/cm2. We demonstrate, though, that higher total In doses can be introduced without forming secondary defects by repetitive subthreshold implants each followed by an anneal to remove the implant damage. While a single 6 X 10(13) In/cm2 implant results in a high density of dislocation loops after annealing, instead using four separate 1.5 X 10(13) In/cm2 implants each followed by an anneal leads to the formation of only a few partial dislocations.