| 摘要 |
PURPOSE:To make an electrode having a large area unnecessary and to facilitate setting up of a small sized light switch having complex structure of electrode by forming Al2O3 thin film on a metal by sputtering or vapor deposition method and forming thin film of a material having higher refractive index than Al2O3 on said Al2O3 thin film. CONSTITUTION:Al2O3 thin film 2 is formed by sputtering or vapor deposition on a metallic substrate 1 comprising Al, Mo, Cu, etc. In this case, it is preferred to form thin film 2 contg. oxide of Cr in order to improve adhesion to the metallic substrate. After forming a layer of Al2O3 or a layer 2 of a mixture of Al with chromium oxide, thin film 3 of a material having higher refractive index than the refractive index of this layer 2 is formed, then, a buffer layer, for example, Ta2O5 thin film 4, is formed. An electrode 5 is formed thereon or on another Al surface obtd. thus a waveguide type device having functionality. By this constitution, the distance between electrodes can be widened and formation of several electrodes is facilitated. |
