Doping of vertical Si nanowires and the carrier profiling

Due to the very promising application of the Si nanowires (SiNW) in the eletrionic, optoelectronic and photovoltaic nano device integration the doping which endows with the functionality to the NW were intensively investigated in the last decades. In this study, individual vertical MBE-grown Si-NWs doped either by ion implantation or by in-situ dopant incorporation are investigated by scanning spreading resistance microscopy (SSRM). The carrier profiles across the axial cross sections of the NWs are derived from the measured spreading resistance values and calibrated by the known carrier concentrations of the connected Si substrate or epi-layer. Furthermore,The potential of the SSRM for three-dimensional (3D) carrier profiling of the NW was demonstrated. The mechanism of the dopant surface segregation and deactivation was discussed.