Original scientific paper
Simulation of MBI reflection of Al thin-films oxidized nonisothermally at T ≷ T2D
Stjepan Lugomer
; Ruđer Bošković Institute, Bijenička c. 54, Zagreb, Croatia, Yugoslavia
Sreten Lekić
; Electrotechnical Faculty, 78000 Banja Luka, Yugoslavia
Mladen Stipančić
; Electrotechnical Faculty, 78000 Banja Luka, Yugoslavia
Midhat Kerenović
; Electrotechnical Faculty, 78000 Banja Luka, Yugoslavia
Abstract
Oxidation of thin Al films in a lineary increasing temperature field, passing the temperature of 2-D melting [T2D (Al) = 639 K], produces inhomogenous oxide films with the gradient of composition mixture of Al2O3, unstehiometric Aloxides., and of unoxidized Al. Composition gradient of the mixture generates the gradient of the refraction index n̂ = n (1 + ik), which changes with oxidation time. This gradient causes a strong exponential damping of interference reflection. The model for simulation of damped interference effects was developed from the model for homogenous dielectric films by inserting the logarithmic oxidation kinetics z (t) = A · In (t - τ), and by inserting the expression k = k0 (e y z(t) - 1) for the gradient of imaginary part of refraction index. [y = const., z = film thickness, t = time; nAl ~ nAL2O3, kAl = 104 kAl2O3]. Excellent fitting of „in situ“ He-Ne laser beam interference reflection measurements was obtained in all the cases considered.
Keywords
Hrčak ID:
332035
URI
Publication date:
10.9.1991.
Visits: 377 *