a1 DuPont Central Research, E356–384 Experimental Station, Wilmington, Delaware 19880
a2 Max-Planck-Institut für Metallforschung, Seestraße 92, D-70174 Stuttgart, Germany
a3 DuPont Central Research, E356–384 Experimental Station, Wilmington, Delaware 19880
a4 Max-Planck-Institut für Metallforschung, Seestraße 92, D-70174 Stuttgart, Germany
a5 DuPont Central Research, E356-384 Experimental Station, Wilmington, Delaware 19880
Precise and accurate knowledge of the optical properties of aluminum nitride (AlN) in the ultraviolet (UV) and visible (VIS) regions is important because of the increasing application of AlN in optical and electro-optical devices, including compact disks, phase shift lithography masks, and AlN/GaN multilayer devices. The interband optical properties in the vacuum ultraviolet (VUV) region of 6–44 eV have been investigated previously because they convey detailed information on the electronic structure and interatomic bonding of the material. In this work, we have combined spectroscopic ellipsometry with UV/VIS and VUV spectroscopy to directly determine the optical constants of AlN in this range, thereby reducing the uncertainty in the preparation of the low-energy data extrapolation essential for Kramers–Kronig analysis of VUV reflectance. We report the complex optical properties of AlN, over the range of 1.5–42 eV, showing improved agreement with theory when contrasted with earlier results.
(Received November 02 1998)
(Accepted August 03 1999)
p1 Present address: Institute for Advanced Materials, Joint Research Centre, European Commission, PO Box 2, NL–1755 ZG Petten, The Netherlands.