Range profiles of 6–10 MeV N ions implanted in silicon

Implantation profiles of 6 to 10 MeV ¹⁵N ions in crystalline silicon have been investigated. Measurements of the profiles at depths from 4 to 7 μm were rendered possible by combining the depth profiling of the ¹⁵N atoms through the ¹⁵N(p, γ) ¹²C reaction and the exfoliation of the surface layer of the samples, accomplished by high dose ⁴He ion bombardment. In this way the range profiles, measured at the exfoliated crater bottom, could be obtained accurately without uncertainties due to straggling of the probing proton beam. The range parameters are compared to those of Monte Carlo calculations using the electronic stopping powers given by J.F. Ziegler, J.P. Biersack and U. Littmark [The Stopping Powers and Ranges of Ions in Matter, Vol. 1 (Pergamon, New York, 1985)]. Projected ranges were observed to be 5%–10% larger and range stragglings 27%–6% smaller than those predicted by Monte Carlo calculations along with the adopted stopping power parametrization.