Process for manufacturing an integrated optical structure and an

Abstract

A process designed for manufacturing an opto-electronic device comprising at least one light-guide integrated in a substrate with a control electrode constituted by a metallic band covering the light-guide and deposited onto the substrate, and an earth-plane integrated in the bottom of the substrate. The process comprises a preliminary step wherein the light-guide is created by doping the substrate for example in a channel adjacent to the upper side of the substrate. In the first step the material of the substrate (e.g. monocrystalline lithium niobate) is chemically reduced by hydrogen for rendering the whole substrate electrically conductive (and consequently opaque). After a second step of partial protective masking, a third step takes place wherein the upper part of the substrate is re-oxidized for restoring a transparent layer comprising the light-guide - the latter characterized by a higher refractive index - and an insulating medium in the upper part of the substrate. In a last step a metallic band is deposited onto the light guide forming with the conductive bottom substrate two electrodes of the opto-electronic device.