Optical properties of titanium containing amorphous hydrogenated carbon films (a-C : H/Ti)

Titanium containing amorphous hydrogenated carbon films have been deposited by reactive magnetron sputtering. Real time laser reflectometry and ex sit u spectrophotometry have served as a means for the determination of the opt ical constants index of refraction n and extinction coefficient k. The expe rimental results are being compared to effective medium theories, modeling the optical constants of the composite material from the ones of amorphous hydrogenated carbon and TiC. We have used the effective medium theories to estimate the bulk stoichiometries which agree with Rutherford backscatterin g experiments but deviate from the surface stoichiometries determined by in situ photoelectron spectroscopy. These deviations can be explained by surf ace diffusion and three dimensional cluster growth. (C) 2000 American Insti tute of Physics. [S0021- 8979(00)03009-7].