CONCENTRATION PROFILES OF PROJECTILES AND RECOILED NITROGEN IN SI AFTER ION-IMPLANTATION THROUGH SI3N4 FILMS

The concentration profiles of ion-implanted boron, phosphorus, and arsenic, and recoil-implanted nitrogen atoms after ion implantation through Si 3N4 films on Si have been measured using secondary ion mass spectrometry. The concentration profiles of the implanted ions in Si after ion implantation through Si3N4 films were found to agree with those implanted into bare Si within experimental errors, with the exception of a shifting of the concentration peak position. The concentration profiles of recoil-implanted nitrogen in Si are generally composed of high-concentration regions with steeply decaying distributions near the silicon surface and the exponential tails whose slopes are independent of ion mass, energy, dose, and film thickness. The concentration level of recoil-implanted nitrogen and maximum penetration range relative to the implanted ion range depend strongly on ion mass, film thickness, and ion energy. It was demonstrated that the concentration profiles for recoiled nitrogen in Si calculated using the Thomas-Fermi interaction potential agree better with the measured profiles than those calculated using 1/r2 potential, such as presented in the theory by Moline et al.