Comparison of effects of pulsed ruby laser and pulsed electron beam annealing of 75As+ implanted silicon

Abstract

Ion‐backscattering, ion‐channeling, and transmission electron microscopy (TEM) have been used to study a series of ion implanted silicon samples that have been annealed with either a pulsed laser or a pulsed electron beam. Single crystal [(001) orientation] silicon samples were implanted with either 35 or 100 keV 75As+ to a dose of ∠1×1016 As/cm2 and subsequently annealed with either a Q‐switched pulsed Ruby laser or the Spire Corporation SPI‐PULSE 5000 electron beam generator. A series of energy densities was used in both cases to optimize results. It was determined from Rutherford backscattering that the as‐implanted profiles have been redistributed in essentially the same manner for both types of anneals, and this indicates that melting and rapid recrystallization has occurred. For the 35 keV 75As+ implanted samples the two techniques produced equivalent anneals with no remaining damage as indicated by channeling and TEM. However, for the 100 keV implants the anneal was not uniform across the sample in the electron beam case and the channeling minimum yields for the major axes ([110], [111], and [100]) were higher than the laser annealed results. In both cases, however, the As substitutionality (97–99%) and minimum yields are better than results obtained from conventional thermal annealing.