Refractive indices of B _<i>x</i> Al _{1− <i>x</i>} N ( <i>x</i> = 0–0.012) and B _<i>y</i> Ga _{1− <i>y</i>} N ( <i>y</i> = 0–0.023) epitaxial layers in ultraviolet region

Abstract

Refractive indices of BxAl1−xN and ByGa1−yN epitaxial layers were determined in the ultraviolet (UV) wavelength range from 230 nm to 600 nm by the light reflectance spectrum. The relative refractive index differences of (AlN/B0.01Al0.99N) and (GaN/B0.02Ga0.98N) heterostructures were 17% at 250 nm and 11% at 370 nm, respectively. These values indicate that an optical waveguide can be organized in the UV to deep-UV spectral region using the nitride semiconductors which include a small amount of boron. The relative refractive index difference of 6% was achieved with only 0.2% and 1.1% of boron for (AlN/BxAl1−xN) and (GaN/ByGa1−yN) heterostructures at 250 nm and 370 nm, respectively. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)