The purpose of this study is to illustrate the effects of the structure of the silicon surface on low-energy implants commonly used in current silicon technology. T o this aim Molecular Dynamics simulations with classical forces are used to study implantation of argon and boron with a kinetic energy in the range from 5eV to 30 eV into a silicon stepped surface. In addition to these calculations, the binding energy of boron atoms embedded in small clusters with a step shape hav e been studied with a quantum mechanical method of a semiempirical type. The purpose of these calculations is to compare the stable sites generated by theimplan ts with the ones attained during thermal treatments under near-equilibrium conditions.