Combined reflection and transmission thin-film ellipsometry: a unified linear analysis

Abstract

, "Combined reflection and transmission thin-film ellipsometry: a unified linear analysis," Appl. Opt. 14, 1652Opt. 14, -1663Opt. 14, (1975 http://www.opticsinfobase.org/ao/abstract.cfm? URI=ao-14-7-1652 Combined reflection and transmission thin-film ellipsometry: a unified linear analysis R. M. A. Azzam, M. Elshazly-Zaghloul, and N. M. Bashara A scheme of combined reflection and transmission ellipsometry on light-transmitting ambient-film-substrate systems is proposed and the required sample design and instrument operation are investigated. A comparative study of the sensitivity of external and internal reflection and transmission ellipsometry is carried out based on unified linear approximations of the exact equations. These approximations are general in that an arbitrary initial film thickness is assumed. They are simple, because a complex sensitivity function is introduced whose real and imaginary projections determine the psi (@) and delta (A) sensitivity factors. Among the conclusions of this paper are the following. (1) External reflection ellipsometry near the Brewster angle of a transparent ambient-substrate system is extremely sensitive to the presence of very thin interfacial films. For example, films as thin as 10-5 A of gold are readily detectable on glass substrates at an angle of incidence 0.30 below the Brewster angle, assuming a measuring wavelength of 5461 A with an ellipsometer of 0.05° precision. (2) The formation of thin nonabsorbing films at the interface between transparent ambient and substrate media is not detectable, to first order, as a change in the ellipsometric angle Q by either internal or external reflection or transmission ellipsometry.

Approximate methods for the optical characterization of inhomogeneous thin films: Applications to silicon nitride films

“…The existence of a rela- tively large gradient of the profile in this film was again indicated by an impossibility to fit the experimental data by means of the WKBJ approximation. The model of the refractive index profile as well as the dispersion model are identical with those used in the optical characterization performed by the WKBJ method (see sub-section 6.1, (10) and (11)). The perfect fits of the experimental data was achieved which is seen in Fig.…”

“…where p(x) = 1 − (1 − x) s and s is the parameter of the model. The dielectric functions at the upper and lower boundaries were calculated using the same dispersion model as in the previous example (see (11)).…”

“…This reality is demonstrated by enormous number of scientific articles and many monographs dealing with optics of thin films. Enormous attention has been devoted to optics of homogeneous thin films in particular (see eg [1][2][3][4][5][6][7][8][9][10][11][12][13]). A less attention has been devoted to optics of inhomogeneous thin films since from the optical point of view these films are more complicated than homogeneous thin films.…”

Towards the application of Al2O3/ZnO nanolaminates in immunosensors: total internal reflection spectroscopic ellipsometry based evaluation of BSA immobilization

“…Ellipsometric parameters () and () in TIRE configurations have different sensitivities [26]. The ellipsometric parameter () was used for the real time signal registration because of its higher sensitivity towards surface changes during BSA immobilization.…”

Use of the Richardson extrapolation in optics of inhomogeneous layers: Application to optical characterization

“…Within the optical characterization and optical synthesis of thin films, inhomogeneous layers play an important role. While there are many works devoted to methods usable in optical characterization and optical synthesis of homogeneous thin films (see, eg, previous studies , less attention has been devoted to the methods enabling us to characterize or perform optical synthesis of inhomogeneous thin films exhibiting refractive index profiles. Therefore, it is necessary to develop new procedures usable in the optics of inhomogeneous layers.…”