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

Published

January 6, 2000

Author(s)

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

Abstract

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 h_epi, above which the LTG-GaAs growth is polycrystalline for T_g - 350 0C, and amorphous for T_g - 180 0C.

Citation

Applied Physics Letters

Pub Type

Journals

Keywords

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

Citation

Gajewski, D. , Guyer, J. and Pellegrino, J. (2000), Real-Time Measurements of the Pseudodielectric Function of Low-Temperature-Grown GaAs, Applied Physics Letters (Accessed April 24, 2024)