Current spreading resistance analyses of ultrashallow dopant profiles in Si take into account effects of carrier spilling and calculate the spreading resistance using a multilayer correction algorithm. However, the analysis of profiles with the dopant sequence lowly doped layer on highly doped layer or substrate does not give accurate results. Reasons for this behavior are investigated by studying effects of probe tip penetration and plastic deformation of Si. Results of loading-unloading experiments on the system OsW probe/Si let us conclude that a metallic Si phase is present beneath the loaded contact. The spatial extent of this metallic phase zone is estimated. The penetration of the probes into the Si samples and the geometry of the probe indents are independent of conductivity type and dopant concentration as shown by atomic force microscopy and scanning electron microscopy investigations. Three-dimensional model calculations check the effect of the depth distribution of penetrating microcontacts of the OsW probes.