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Optical constants of (Al0.98Ga0.02)xOy native oxides



K. J. Knopp, Richard Mirin, David H. Christensen, Kristine A. Bertness, Alexana Roshko, R A. Synowicki


We report the optical constants of oxidized crystalline and low-temperature-grown (LTG) Al0.98Ga0.02As films, as determined by variable angle spectroscopic ellipsometry. Data were acquired at three angles of incidence over 240-1700nm and fit to a Cauchy dispersion function. For oxidized crystalline material, we observe a variation in the real index of 5% for layer thickness variations of 6%. We show that upon oxidation, LTG material can expand by >25% while crystalline material contracts by <2%. Atomic force microscopy analysis indicates thickness-dependent variations in the oxide microstructure. Additionally, an optical scattering loss of 1.1×10-6 is calculated based on surface roughness measurements for a thin layer of oxidized crystalline material.
Applied Physics Letters


Knopp, K. , Mirin, R. , Christensen, D. , Bertness, K. , Roshko, A. and Synowicki, R. (1998), Optical constants of (Al<sub>0.98</sub>Ga<sub>0.02</sub>)<sub>x</sub>O<sub>y</sub> native oxides, Applied Physics Letters, [online], (Accessed July 24, 2024)


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Created December 13, 1998, Updated October 12, 2021