Title :
Optical properties of GaAs1-yNy (y⩽0.037)
Author :
Leibiger, G. ; Rheinländer, B. ; Gottschalch, V. ; Schubert, M. ; Sik, J. ; Lippold, G.
Author_Institution :
Dept. of Semicond., Leipzig Univ., Germany
Abstract :
The optical properties of MOVPE GaAs1-yNy (0⩽y⩽3.7%) single layers and GaAsN/GaAs superlattices are studied using spectroscopic ellipsometry and Raman spectroscopy. We analyse the dielectric function near the critical points E0, E1 and E1+Δ1 using Adachi´s critical-point model. For the layers and the GaAsN superlattice sublayers we observe the strong reduction of the band gap. Contrary to the red shift of the gap energy E0, the E1 and E 1+Δ1 energies are linearly blue shifted with increasing y. For 0⩽y⩽1.65% the observed blueshift of the E1 energy is well explained by the combination of the effects of biaxial (001) strain and alloying. In the Raman spectra the redshift and broadening of the GaAs LO1 mode and the existence of the nitrogen local mode LO2 near 470 cm-1 have been detected
Keywords :
III-V semiconductors; MOCVD coatings; Raman spectra; dielectric function; ellipsometry; energy gap; gallium arsenide; gallium compounds; semiconductor epitaxial layers; semiconductor growth; vapour phase epitaxial growth; wide band gap semiconductors; 470 cm-1; Adachi´s critical-point model; GaAs LO1 mode; GaAs1-yNy; GaAsN; GaAsN/GaAs superlattices; MOVPE; Raman spectra; Raman spectroscopy; band gap; biaxial (001) strain; critical points; dielectric function; optical properties; spectroscopic ellipsometry; Capacitive sensors; Dielectrics; Ellipsometry; Epitaxial growth; Epitaxial layers; Gallium arsenide; Optical superlattices; Photonic band gap; Raman scattering; Spectroscopy;
Conference_Titel :
Advanced Semiconductor Devices and Microsystems, 2000. ASDAM 2000. The Third International EuroConference on
Conference_Location :
Smolenice
Print_ISBN :
0-7803-5939-9
DOI :
10.1109/ASDAM.2000.889474
