Fabrication of short-range ordered nanoholes on silicon surfaces by electron irradiation

Silicon surface nanoholes, which are small pits introduced spontaneously on the electron exit surfaces of silicon foils by electron irradiation, distribute orderly in a short range. The nearest-neighbor distance and mean opening area of the nanoholes exhibit an Arrhenius-like behavior at high temperatures. The formation mechanism is discussed in terms of the migration of surface vacancies under electron irradiation conditions, and the activation energy of the migration is estimated to be 0.3 +/- 0.04 eV.