Longitudinal and transversal moments of the distribution of boron ions implanted in silicon in the MeV energy range
Boron ions have been implanted in silicon at energies ranging from 0.5 to 3 MeV at normal (θ ⋍ 7°) and oblique (θ = 60°) incidence in order to study their longitudinal and transversal distributions. The profiles, measured using both C- V and SIMS methods, were characterized by their moments, obtained by adjustement to a Pearson IV function. The projected range Rp varies linearly with energy above 1 MeV, indicating that the region of maximum stopping power is reached. The transversal straggling agrees fairly well with the TRIM'89 Monte Carlo calculation while the longitudinal dispersion deviates slightly at increasing energy. This, together with the values of the skewness, which is smaller than expected theoretically, seems to indicate that fluctuations of the electronic stopping could affect implantation at the considered energies.