Reactive dynamics analysis of critical Nb₂O₅ sputtering rate for drum-based metal-like deposition

Drum-based metal-like film deposition for oxide was investigated using single wavelength in situ monitoring. The data were used to investigate the oxidation mechanism using combined second-order kinetic and parabolic models. A critical Nb₂O₅ deposition rate of 0.507 nm/s was found at drum rotation of 1 rev/s. However, Nb₂O₅ samples prepared at varying deposition rates showed that the deposition rate must be much lower than the critical deposition rate to achieve reasonable absorption. Thus simulation for the volume-fraction of metal in the oxide layer was done using effective medium approximation and a distribution function. Simulation gave high agreement with experimental results and allows the prediction of extinction coefficients at various deposition rates.