The 400 keV Er and Nd ions were implanted into Si1N1.375H0.603, each kind of ions were performed at 0 and 60 incident angles, respectively. The mean projected ranges as well as range straggling and lateral spread of implanted ions were studied by using Rutherford backscattering (RBS) of 2.1 MeV He ions. The obtained experimental values were compared with the calculated values by TRIM'96. The results show that ranges are in good agreement with each other; for range straggling and lateral spreads the maximum difference between the experimental and calculated values are 22 and 21%, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.