Simultaneous determination of optical constants, local thickness, and local roughness of thin films by imaging spectroscopic reflectometry

Logo poskytovatele
Logo poskytovatele
Logo poskytovatele

Varování

Publikace nespadá pod Pedagogickou fakultu, ale pod Přírodovědeckou fakultu. Oficiální stránka publikace je na webu muni.cz.
Název česky Současné určení optických konstant, lokální tloušťky a lokální drsnosti tenkých vrstev pomocí zobrazovací spektroskopické refektometrie
Autoři

NEČAS David OHLÍDAL Ivan VODÁK Jiří OHLÍDAL Miloslav FRANTA Daniel

Rok publikování 2015
Druh Článek ve sborníku
Konference Conference on Optical Systems Design - Optical Fabrication, Testing, and Metrology V
Fakulta / Pracoviště MU

Přírodovědecká fakulta

Citace
Doi http://dx.doi.org/10.1117/12.2190091
Obor Fyzika pevných látek a magnetismus
Klíčová slova thin films; roughness; scalar diffraction theory; Rayleigh-Rice theory; spectrophotometry; ellipsometry; imaging techniques; zinc selenide
Popis A new optical characterization method based on imaging spectroscopic reflectometry (ISR) is presented and illustrated on the characterization of rough non-uniform epitaxial ZnSe films prepared on GaAs substrates. The method allows the determination of all parameters describing the thin films exhibiting boundary roughness and non-uniformity in thickness, i.e. determination of the spectral dependencies of the optical constants, map of local thickness and map of local rms values of heights of the irregularities for the rough boundaries. The local normal reflectance spectra in ISR correspond to small areas (37x37 pm2) on the thin films measured within the spectral range 270-900 nm by pixels of a CCD camera serving as the detector of imaging spectrophotometer constructed in our laboratory. To our experience the small areas corresponding to the pixels are sufficiently small so that the majority of the films can be considered uniform in all parameters within these areas. Boundary roughness is included into the reflectance formulas by means of the scalar diffraction theory (SDT) and the optical constant spectra of the ZnSe films were expressed by the dispersion model based on the parametrization of the joint density of electronic states (PJDOS). In general, there is a correlation between the searched parameters if the individual local reflectance spectra are fitted separately and, therefore, the local reflectance spectra measured for all the pixels are treated simultaneously using so called multi-pixel method in order to remove or reduce this correlation and determine the values of all the parameters with a sufficient accuracy. The results of the optical characterization of the same selected sample of the epitaxial ZnSe thin film obtained using the method presented here and combined method of variable-angle spectroscopic ellipsometry, spectroscopic reflectometry and single-pixel immersion spectroscopic reflectometry are introduced in the contribution as well.
Související projekty:

Používáte starou verzi internetového prohlížeče. Doporučujeme aktualizovat Váš prohlížeč na nejnovější verzi.