Photoluminescence of low-energy B plus -implanted silicon under ultraviolet light excitation

We measured photoluminescence (PL) spectra of Si implanted with 0.5 keV Bions to doses varying from 1.0 x 10(14) to 4.0 x 10(15) cm(-2). We compared the PL spectra under ultraviolet (UV) light (the 351 and 364 nm lines of a n Ar ion laser) excitation with those under visible light (the 488 nm line of an Ar ion laser) excitation. The emission due to the impurity band of B was observed only in the case of the UV light excitation, indicating that t he activated B atoms were located in the shallow region of the order of 10 nm. The II line at 1.02 eV and the broad band consisting of two bands with peaks at 0.82 and 0.97 eV were also observed in the PL spectra. They are re lated to different types of point defect clusters. Comparing the PL spectra under different light excitations, we conclude that the distribution of th e defects induced by ion implantation is not restricted in the shallow regi on of the implanted B atoms even in the as-implanted sample. We also conclu de that the 0.97 eV defect extends to the region deeper than the region of the 0.82 eV defect after the annealing.