Concentrations of deep hole traps were measured in a set of hydride vapor phase epitaxy grown samples with thicknesses varying from 2.6 to 68 μm. Results were obtained from low temperature capacitance–voltage measurements before and after illumination and from deep level transient spectroscopy measurements with optical injection (ODLTS). The former revealed the presence of high densities (∼1015 to 1016 cm−3) of hole traps whose concentration decreased with sample thickness in a manner similar to that found for the dislocation density. Capacitance versus temperature measurements in the dark and after illumination suggested that these traps form a band of states rather than a single level in the GaN band gap. It is suggested that such states could be associated with dislocations. The main hole traps observed by ODLTS were deep hole traps, of energy near Ev+0.9 eV. Their density was also observed to substantially decrease with sample thickness.
Polyakov, A. Y.,
Smirnov, N. B.,
Govorkov, A. V.,
Look, D. C.,
Molnar, R. J.,
& Osinsky, A. V.
(2002). Deep Hole Traps in N-GaN Films Grown by Hydride Vapor Phase Epitaxy. Journal of Applied Physics, 91 (10), 6580-6584.
Copyright © 2002, American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in the Journal of Applied Physics 91.10, and may be found at http://jap.aip.org/japiau/v91/i10/p6580_s1