Fourier methods allow the separation of baseline, information, and noise in reciprocal space, thereby permitting more accurate derivative lineshapes to be calculated, more accurate interpolations and Kramers-Kronig transformations to be performed, and more accurate estimates to be made of the critical point parameters that describe structure in optical spectra. These techniques are discussed and applied to ellipsometrically measured pseudodielectric function spectra of the semiconductor alloy sequences AlxGal-xAs and GaAs1-xPx. The x dependence of the El and El + Δl critical point energies of AlxGa1-xAs shows definite departures from quadratic behavior. In the E0 - E2 spectral region significant level crossings are observed for AlxGa1-xAs, while the corresponding structures for GaAs1-xPx shift uniformly with x.

Date Published: 10 May 1984
PDF: 9 pages
Proc. SPIE 0452, Spectroscopic Characterization Techniques for Semiconductor Technology I, (10 May 1984); doi: 10.1117/12.939292

Published in SPIE Proceedings Vol. 0452:
Spectroscopic Characterization Techniques for Semiconductor Technology I
Robert S. Bauer; Fred H. Pollak, Editor(s)