Simon JITIAN

THE DETERMINATION OF THICKNESS AND OPTICAL
CONSTANTS FOR POLYMETHYL METHACRYLATE FILM
FROM IR REFLECTANCE SPECTRA
The transmittance values measured in IR reflection-absorption (RA)
spectra can be used to determine the optical constants of dielectric films laid on
solid substrates. When the recorded spectra show interference fringes, one can
determine the film thickness. The film thickness was obtained from the
reflexion-absorption IR spectra recorded at two different incidence angles.
To obtain the optical constants of polymethylmetacrilat films laid on
steel we used dispersion analysis. Using dispersion analysis offers the
advantage of processing a large volume of data.
Keywords: reflection absorption, optical constants, IR spectra,
dispersion analysis
Cuvinte cheie: reflexie-absorbţie, constante optice, spectre IR, analiza
de dispersie

25 DETERMINAREA GROSIMII ŞI A CONSTANTELOR

The paper presents a graphical method for the simultaneous
determination of thickness and optical constants of a superficial, optically
absorbent film. The data used have been obtained by ellipsometrical
measurements of a superficial layer of uneven thickness at several points.
The thickness and optical constants are determined for PMMA films
deposited on a copper surface highly polished.
Cuvinte cheie: constante optice, elipsometrie, film superficial, metodă
grafică
Keywords: optical constants, ellipsometry, surface film, graphical
method

21 DETERMINAREA ELIPSOMETRICĂ A GROSIMII ŞI A