Extraction of Parameters of Homogeneous Nonideal Schottky Contacts Using I-V Measurements

Abstract

A novel method to determine effective barrier heights in homogeneous nonideal Schottky contact from I–V measurements is proposed. This method takes into account the different mechanisms of current flow through the metal‐semiconductor interface. The total current has been expressed as the sum of two independent terms which are: (i) the thermionic current where the ideality factor value is equal to one and (ii) the contribution of different transport mechanisms. The second term responds to a general expression of the thermionic emission theory where the barrier height and the ideality factor are voltage dependent. The effective barrier height is found by means of subtraction of the transport mechanisms term from the total current. The method was applied to a group of I–V curves which were simulated numerically using the well known theoretical expression of different transport mechanisms.

Current-Voltage Characteristic and Schottky Barrier Height of the GaAlAsSb(p)/GaSb(n+) Heterostructure

“…Like that, other kinds of charge transport mechanisms contribute to the current with the thermoionic emission of holes over the barrier, making difficult the determination of accurate values of the heterostructure parameters I s , R s and n [18][19][20]. However, the behavior of the I-V characteristic allows the use of other methods, initially expected for Schottky diodes, to determine R s and n. These techniques are based on the following expressions [21,22]:…”