NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Optical constants of (Al0.98Ga0.02)xOy native oxides
Published
Author(s)
K. J. Knopp, Richard Mirin, David H. Christensen, Kristine A. Bertness, Alexana Roshko, R A. Synowicki
Abstract
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.
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], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=14955
(Accessed October 11, 2025)