About the determination of the Schottky barrier height with the C-V method

On the basis of general notions about Schottky barrier contacts (SBC) with the insulating layer and interface states (ISs) communicating with semiconductor and metal (when their influence results in the linear bias-dependence of the barrier height and the ideality factor n = const), it is shown that the barrier height determined with C-V method is defined with a simple expression: phi(bc) = n phi(b0) - (n - 1)(phi(s) + V-2), practically corresponding to the flatband barrier height expression determined from I-V-characteristic: phi(bf) = n phi(b0) - (n - 1)phi(s). The apparent difference is related to the difference in implementation of the flatband condition in both cases. Earlier, the close correspondence of values phi(bc) and phi(bf) was only known for the ideal Bardeen model, practically excluding values n > 1. The received result is also proved by the detailed analysis of possible conditions of determining the SBC capacity (different frequencies of the test signal, presence or absence of ISs, and their communication with semiconductor and/or metal). It is essential that the measured barrier height phi(bc) remains almost independent of the frequency of the test signal and is determined with the relation between the applied voltage and its part dropping in the barrier only. (C) 2011 American Institute of Physics. [doi:10.1063/1.3561372]