Fabrication of Optically Inhomogeneous Titanium Dioxide Films by Ion Assisted Deposition Method

Structures and Properties of Inhomogeneous Films

抄録

It is well known that titanium dioxide films, deposited by conventional electron beam gun, are homogeneous. Controlling acceleration voltage and current applied to the ion gun continuously during ion assisted deposition by additional Kaufman type ion gun, large degree of intentionally produced inhomogeneous titanium dioxide films are obtained. There exist both types of positively and negatively inhomogeneous films. These optical properties and relationships among their film structures are investigated by the terms of surface topology by surface profilometer and cross-sectional view by scanning electron microscope. Positively inhomogeneous films show a linear refractive index change along film thickness, but the negatively inhomogeneous films possess nonlinear nature and still need to find the appropriate deposition condition, which gives a linear refractive index profile. For this purpose, the films are further characterized by an ellipsometer. Finally the results are compared with those obtained from the macroscopic structure model for the inhomogeneous films.