Study of Schottky barrier of Ni on p-GaN.

The Schottky barrier characteristics of Ni on p-GaN have been investigated using current–voltage–temperature (I–V–T) and capacitance–voltage characteristics (C–V) measurements. Barrier height values ranging from 2.68 to 2.87 eV were obtained from C–V measurements. The temperature dependence of I–V characteristics clearly indicated the dominance of tunneling current in the transport mechanism of the diodes, therefore, barrier height determination using I–V measurements can lead to erroneous results, as indicated by the wide range of barrier heights reported in the literature. Acceptor concentration, deduced from C–V measurements, was found to be of 10[sup 19]/cm[sup 3] within 200 Å of the sample surface, and tapered off to be ∼10[sup 18]/cm[sup 3]. These values are 10–100 times higher than the hole concentration of ∼10[sup 17]/cm[sup 3] obtained from Hall measurements. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]