TRANSMISSION ELECTRON-MICROSCOPY ANALYSIS OF HEAVILY AS-DOPED, LASER, AND THERMALLY ANNEALED LAYERS IN SILICON

The extended defects in laser activated and subsequently thermally annealed high concentration arsenic layers have been investigated in a range of surface concentrations from 2.3×1020 to 1.9×1021 As/cm3 with transmission electron microscopy. We observe a rapid change in the density of dislocation loops with dose which is indicative of a homogeneous nucleation mechanism. The number of atoms bound by the defects is insufficient to account directly for all of the inactive arsenic. The defects lie uniformly inside the As layer up to the junction depth, which suggests that As inactive complexes are aiding the loop formation. Our results support the proposition that arsenic deactivation injects silicon interstitials. © 1995 American Institute of Physics.