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Real-Time Measurements of the Pseudodielectric Function of Low-Temperature-Grown GaAs



Donald A. Gajewski, Jonathan E. Guyer, Joseph G. Pellegrino


We present real-time, in situ spectroscopic ellipsometry (SE) measurements of the pseudodielectric function <ε(E)> = <ε(E)> + i<ε2(E)> of low-temperature-grown GaAs (LTG-GaAS) layers on GaAs (001) substrates at growth temperatures from Td8^ = (180 TO 300) 0C. The SE measurements reveal that for LT-GaAs, the <ε2(E)> peak associated with the interband critical point E1 broadens and decreases in amplitude monotonically with increasing excess arsenic point defect density. The SE measurements during the growth also display a clear signature of exceeding the critical epitaxial thickness limit hepi, above which the LTG-GaAs growth is polycrystalline for Tg - 350 0C, and amorphous for Tg - 180 0C.
Applied Physics Letters


spectroscopic ellipsometry, low temperature GaAs, in situ, dielectric function, optical properties, photodetectors


Gajewski, D. , Guyer, J. and Pellegrino, J. (2000), Real-Time Measurements of the Pseudodielectric Function of Low-Temperature-Grown GaAs, Applied Physics Letters (Accessed February 26, 2024)
Created January 5, 2000, Updated October 12, 2021