OPTICAL-PROPERTIES OF ZR FILMS GROWN UNDER ION-BOMBARDMENT

Zr films (300-600 nm) have been deposited on Si[100] in a double-ion-b eam system (residual pressure, less than 10(-7)Torr) using Ar+ for bot h sputtering and irradiation of the growing film. The films have been optically characterized by spectroscopic phase-modulated ellipsometry in the range 1.5-4.5 eV as a function of the deposition variables. The results show significant changes in the real part n and in the imagin ary part k of the complex refractive index (N = n + ik). These changes mainly depend on the flux and energy of the Ar+ ions impinging the gr owing film. Furthermore, the stability of the films against the exposu re to atmosphere and annealing in vacuum (10(-7)Torr) was also investi gated. The results are discussed in terms of packing densities, damage and surface oxidation of the films.