Measurement of the effect of plasmon gas oscillation on the dielectric properties of p- and n-doped AlxGa1-xN films using infrared spectroscopy

Abstract

We report on the application of infrared (IR) spectroscopy as an approach to nondestructive optical method for quantitative measurement of relevant optoelectronic properties in complex multilayer systems. We developed a numerical technique to analyze quantitatively the dielectric properties and plasmon gas characteristics from infrared reflectivity measurements. The developed technique is based on the combination of Kramers-Kronig theorem with the classical theory of electromagnetic wave propagation in a system of thin films. We applied the approach to deduce the dielectric properties and plasmon gas characteristics in p- and n-doped AlGaN alloys of various compositions, deposited on AlN(100 nm)/GaN(30 nm)/Al2O3. The results agreed with the electrical measurements, and the back calculation reproduced satisfactory the reflectivity measurements, demonstrating the accuracy of the developed technique. © 2013 AIP Publishing LLC.