OPTICAL AND ELECTRICAL MEASUREMENTS ON CO2 COVERED COPPER-FILMS

Thin polycrystalline copper films are deposited in a special UHV cell on glass substrates and are covered step by step with CO2. The optical and electrical properties of the films are studied in-situ by means o f ellipsometry and resistivity measurements. The properties of the cle an films correspond to literature data. In the case of monolayer adsor ption of CO2, the changes in the ellipsometrical angles are delta Delt a approximate to +1 degrees and delta psi approximate to +0.1 degrees, similar to the Cu/O and Cu/CO systems. Three-dimensional island growt h leads to a drastical increase of delta Delta and delta psi by severa l orders of magnitude. The resistivity first quickly de creases and th en slowly reapproaches the initial value. This marked kinetics is quan titatively interpreted on the basis of a diffusion model.