CHARACTERIZATION OF OPTICALLY-ACTIVE DEFECTS CREATED BY NOBLE-GAS ION-BOMBARDMENT OF SILICON

The modification in the G-line (969.5 meV) and the C-line (789.4 meV) photoluminescence (PL) intensities were studied as a function of the f luence, energy, and mass of the bombarding ions (He, Ne, Ar, and Kr). The intensities of the luminescent lines induced by 1 keV Ne bombardme nt were found to decrease with increasing dose after reaching a maximu m at about 1x1O(12) ions/cm(2). Considerable reductions in the intensi ties of the G-and C-lines were also recorded during bombardment using heavier noble gas ions and they have been attributed to the higher rat es of nuclear energy deposition with increasing bombarding ion mass. T he incident ion energy at which the PL intensities of the spectral lin es reached their maximum values was found to be dependent on the ion m ass and fluence. We have explained the decrease in PL intensities of t he G-line and C-line to be due to the introduction of increased amount s of nonradiative recombination centers with increasing incident ion d ose and mass. Further, the integral sum of defects induced during bomb ardment as a function of projected ion range and excitation depth of t he Ar-ion laser has been used to qualitatively describe the decrease i n the intensities of the two lines. (C) 1998 American Institute of Phy sics.