Title :
Optical properties of Al1-xInxN thin films determined by spectroscopic ellipsometry
Author :
Kasic, A. ; Schubert, M. ; Rheinlander, B. ; Off, J. ; Scholz, F. ; Herzinger, C.M.
Author_Institution :
Fakultat fur Phys. und Geowissenschaften, Leipzig Univ., Germany
Abstract :
Infrared spectroscopic ellipsometry is used to study the influence of strain and composition on the transverse-optical phonon mode of E1 symmetry in hexagonal Al1-xInxN films for indium contents of 0.11⩽x⩽0.22. The 0.1 to 0.2 μm thick films were grown on thick slightly compressively strained α-GaN buffer layers, or directly on [0001] sapphire by metal organic vapor phase epitaxy. The Al1-xInxN E1 (TO) phonon shows a one-mode behavior in contrast to recent theoretical predictions. Films grown on GaN reveal the influence of strain on the phonon mode frequencies due to pseudomorphic film growth. Al1-xInxN deposited directly on [0001] sapphire possesses phonon modes which indicate fully relaxed film growth
Keywords :
III-V semiconductors; MOCVD coatings; aluminium compounds; ellipsometry; indium compounds; infrared spectra; phonon spectra; semiconductor growth; semiconductor thin films; wide band gap semiconductors; 0.1 to 0.2 mum; Al1-xInxN thin films; AlInN; E1 symmetry; IR spectroscopic ellipsometry; composition; optical properties; phonon mode frequencies; phonon modes; pseudomorphic film growth; strain; transverse-optical phonon mode; Buffer layers; Capacitive sensors; Ellipsometry; Indium; Infrared spectra; Optical buffering; Optical films; Phonons; Spectroscopy; Thick films;
Conference_Titel :
Compound Semiconductors, 2000 IEEE International Symposium on
Conference_Location :
Monterey, CA
Print_ISBN :
0-7803-6258-6
DOI :
10.1109/ISCS.2000.947208
