About theoretical calculation of semiconductor's surface images for closely spaced semiconductor and metal in STM

摘要

The theoretical method of the direct calculation of the potential relief of the semiconductor surface for system of semiconductor - vacuum gap - metal (SVM), which is in applied voltage U, is proposed. The calculations are based on the assumption that the metal (tip) provides the point dipole in each point of the semiconductor surface in a result of its scanning in STM. Fermi level pinning in the small voltage U is specified by the redistribution of the charge on the dipole layer (really on the semiconductor surface). It is shown that the charge density on the interface is the characteristic of the SVM system in contact and is the function of the macroscopic (screening) properties of the metal and semiconductor and also of the microscopic structure of their interface. The spatial distribution of the potential barrier V(r-bar,U) and its change in an applied voltage U is calculated for example of the n-Si(100)/Vac/W structure.