Abstract The nanomechanical properties of single crystalline silicon samples has gained wide attention in recent years, because of the abnormal loading effects, caused by the pressure‐induced phase transformation of silicon. To further enlighten the phenomenon bulk, ion‐implanted, single crystal Si samples have been studied by nanoindentation experiments, and by atomic force microscopy (AFM). The implantation of Si wafers was carried out by P ions at 40 KeV energy, influencing the defect density and structure of the Si material in shallow depth at the surface. Our experiments provide consistent evaluation of Young's modulus and hardness of the samples (measured with Berkovich‐, spherical‐ and cube corner indenters), statistics of the pop‐in and pop‐out effects during the indentation, and interesting results about the piling‐up behavior of the Si material. The plastic work on the sample was also evaluated in cyclic indentation experiments by calculating the area of the hysteresis loops in the load curve. Copyright © 2008 John Wiley & Sons, Ltd.