Share Email Print

Proceedings Paper

Optical anisotropy of GaN/sapphire studied by generalized ellipsometry and Raman scattering
Author(s): Chunhui Yan; H. Walter Yao; James M. Van Hove; Andrew M. Wowchak; Peter P. Chow; John M. Zavada
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Generalized variable angle spectroscopic ellipsometry (VASE) and Raman scattering have been employed to study the optical anisotropy of GaN/Sapphire structures. The GaN films were grown hydride vapor phase epitaxy and molecular beam epitaxy on both m-plane and c-plane sapphire ((alpha) -Al2O3) substrates, respectively. Anisotropic optical phonon structure of sapphire have been measured, based on which the optical axis of sapphire substrate has been determined. A 541 cm-1 TO phonon of GaN grown on m-plane sapphire substrate has been discovered experimentally which is due the coupling of A1 and E1 TOs. Optical axis orientation of GaN film on m-sapphire has been fully determined by the anisotropic angular dependence of the coupled TO phonon. Off-diagonal elements Apst and Aspt of transmission VASE (TVASE) are very sensitive parameters related to the optical anisotropy. The optical axis orientation of GaN on m-sapphire has also been accurately determined by TVASE at two special sample positions. The optical anisotropy due to GaN film and sapphire substrate has been successfully separated at 90 degree(s) samples position allowing to study the optical anisotropy of GaN film only.

Paper Details

Date Published: 14 April 1999
PDF: 12 pages
Proc. SPIE 3621, Light-Emitting Diodes: Research, Manufacturing, and Applications III, (14 April 1999); doi: 10.1117/12.344490
Show Author Affiliations
Chunhui Yan, Univ. of Nebraska/Lincoln (United States)
H. Walter Yao, Univ. of Nebraska/Lincoln (United States)
James M. Van Hove, SVT Associates (United States)
Andrew M. Wowchak, SVT Associates (United States)
Peter P. Chow, SVT Associates (United States)
John M. Zavada, U.S. Army Research, Development and Standardization Group (United States)

Published in SPIE Proceedings Vol. 3621:
Light-Emitting Diodes: Research, Manufacturing, and Applications III
E. Fred Schubert; Ian T. Ferguson; H. Walter Yao, Editor(s)

© SPIE. Terms of Use
Back to Top