Size effect of electromagnetic constitutive characteristics of ultrathin Al films

The ultrathin aluminum films with thickness in the range of 2 similar to 60 nm have been deposited by de magnetron sputtering apparatus. Reflectance and transmittance of the obtained samples were measured with a WFZ-900-D4 UV/VIS spectrophotometer. The optical constant (n, k) and permittivity (epsilon', epsilon ") were determined by applying Newton-Simpson recurrent substitution method. The results indicate that the electromagnetic constitutive characteristic of ultrathin aluminum films is a function of thickness and has obvious size effect.