  We have investigated field evaporation of grounded arsenic (As) doped silicon
(Si) clusters consist of 52 atoms with density functional theory to mimic Si
nano structures of hundreds of nanometers long standing on a substrate. Six
cluster structures with different As doping concentrations and dopant locations
are studied. The critical evaporation electric fields are found to be lower for
clusters with higher doping concentrations and doping sites closer to the
surface. We attribute the difference to the difference in binding energies
corresponding to the different As-doping concentrations and to the doping
locations. Our theoretical study could shed light on the stability of nano
apexs under high electric field.
