J. Phys. IV France 09 (1999) Pr8-1195-Pr8-1202
Characterisation of complex multilayer structures using spectroscopic ellipsometryM.I. Alonso1, M. Garriga1, C. Domínguez2 and A. Llobera2
1 Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas, Campus de la UAB, 08193 Bellaterra, Spain
2 Institut de Microelectrònica de Barcelona, Consejo Superior de Investigaciones Científicas, Campus de la UAB, 08193 Bellaterra, Spain
We have developed a fit method that allows detailed analysis of complicated ellipsometric spectra, such as those of thick (~10µm) multilayer structures found in modern integrated optics devices. Ellipsometry should be the natural choice for thorough nondestructive characterisation of those heterostructures, but extraction of the required parameters is often impracticable by common approaches. Our fit procedure is based in spline parametrisations of the unknown optical functions and is applicable to materials either with a smooth optical response or displaying sharp electronic transitions in the analysed energy range. We have applied our method to characterise PECVD-grown non-stoichiometric silicon oxides (SiOx) and thick waveguide structures based on these materials.
© EDP Sciences 1999