The impact parameter dependence of the energy straggling of protons into GaAs

Abstract The present work examines the impact parameter dependence of the electronic straggling, Q e , for protons implanted into GaAs, by comparing the two cases of aligned and random implantations. A Monte-Carlo simulation program based on the ACOCT code is used, and the results are compared to ion profile measurements obtained by SIMS and ERDA. The simulation yields electronic stopping power, S e , and electronic straggling, Q e values for ions inside the crystal all along their slowing-down process. The energy dependence of Q e is also derived. The calculations reveal the impact parameter dependence of Q e qualitatively well.