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In-situ ellipsometric studies of optical and surface properties of GaAs(100) at elevated temperaturesA rotating-polarizer ellipsometer was attached to an ultrahigh vacuum (UHV) chamber. A GaAs(100) sample was introduced into the UHV chamber and heated at anumber of fixed elevated temperatures, without arsenic overpressure. In-situ spectroscopic ellipsometric (SE) measurements were taken, through a pair of low-strain quartz windows, to monitor the surface changes and measure the pseudodielectric functions at elevated temperatures. Real-time data from GaAs surface covered with native oxide showed clearly the evolution of oxide desorption at approximately 580 C. In addition, surface degradation was found before and after the oxide desorption. An oxide free and smooth GaAs surface was obtained by depositing an arsenic protective coating onto a molecular beam epitaxy grown GaAs surface. The arsenic coating was evaporated immediately prior to SE measurements. A comparison showed that our room temperature data from this GaAs surface, measured in the UHV, are in good agreement with those in the literature obtained by wet-chemical etching. The surface also remained clean and smooth at higher temperatures, so that reliable temperature-dependent dielectric functions were obtained.
Document ID
19950047805
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Yao, Huade
(Nebraska Univ. Lincoln, NE, US, United States)
Snyder, Paul G.
(Nebraska Univ. Lincoln, NE, US, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1991
Publication Information
Publisher: Elsevier Sequoia S.A.
Subject Category
Solid-State Physics
Accession Number
95A79404
Funding Number(s)
CONTRACT_GRANT: NAG3-154
Distribution Limits
Public
Copyright
Other

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