  We report the uniaxial anisotropic optical constants of Wurtzite type AlN
films deposited on Si (100) substrate using DC reactive magnetron sputtering as
a function of growth temperature (Ts, 35 to 600 C). Evolution of optical
properties with Ts is investigated by Spectroscopic Ellipsometry (SE)
technique. Thickness and roughness of these films are determined from the
regression analysis of SE data, which are corroborated using TEM and AFM
technique. Highly a-axis oriented AlN film grown at 400 C, exhibits high n and
low k at 210 nm (deep-UV region) with a small birefringence and dichroism near
to band edge, which can be used in isotropic deep UV optoelectronic device
applications. All these AlN films exhibit transparent nature from near-infrared
(NIR) to 354 nm, where optical band gap energies vary between 5.7 to 6.1 eV.
