Extending the detection limit of dopants for focused ion beam prepared semiconductor specimens examined by off-axis electron holography

Silicon specimens containing p-n junctions have been prepared for examination by off-axis electron holography using focused ion beam (FIB) milling. FIB milling modifies the surfaces of the specimens due to gallium implantation and the creation of defects which has the effect of reducing the active dopant concentration measured during electrical characterization. Here we show that although this damage can be removed by using low temperature annealing, the presence of surface charge will modify the electrical potentials in the specimens and limit the dopant concentration that can be measured. (C) 2009 American Institute of Physics. [doi:10.1063/1.3195088]