On the field penetration into semiconductors in the field ion microscope

Abstract

The calculation of field penetration in semiconductors and consequent band bending during field ionization/evaporation is discussed. The shielding by surface states is also taken into account. The Si(111) face example demonstrates that neglection of surface states may give unrealistic high band bending values. Because of the lack of reliable data for the density of surface states, a possible maximal band bending has been calculated for GaAs. Its value in the case of an external applied field of 1 V A ̊ may be such smaller as formerly assumed in recent works.