Studying of barrier height and ideality factor relation in the nano sized Au-n type Si Schottky diodes

Abstract

The results of formation of the operating potential barrier height ( Φ в) of inhomogeneous Schottky diodes (SD) in view of an additional electric field in the near contact region of the semiconductor and features of its dependence on the external applied voltage are presented. A correlation, between SD heterogeneity and dependence between potential barrier height ( Φ в) and ideality factor ( n), is presented. Using conducting probe atomic force microscope (CP-AFM) techniques, it is shown that Au/n-Si diodes consist of sets of parallel-connected and cooperating nano diodes with the contact surfaces sizes in the order of 100–200 nm. The effective Φ в and ideality factors of the SD have been obtained from the current–voltage ( I– V) characteristics, which were measured using a CP-AFM along a contact surface. It was experimentally shown that the forward and reverse part of I– V characteristics and their effective Φ в and ideality factors of the identically fabricated nano-SD differ from diode to diode. The Φ в for the nano-SD has ranged from 0.565 to 0.723 eV and ideality factor from 1.11 to 1.98. No correlation can be found between the Φ в and ideality factor. The Φ в distribution obtained from the I– V characteristics has been fitted by a Gaussian function but the ideality factor distribution could not be fitted by a Gaussian function.