Device having integrated optical and copper conductors and method of fabricating same

A method is provided for making optical waveguide structures in a semiconductor device wherein a rectangular cross-section low index of refraction material is encapsulated in a trench by a high index of refraction material. The waveguide structures may be made in a device containing copper conductors in trenches by forming new trenches to hold the optical waveguide. Copper conductor containing trenches may also be made in an electronic component containing waveguide structures and a further method is provided for forming an optical waveguide structure by replacing a copper containing trench with the waveguide structure in an electronic component having a plurality of copper containing trenches. All the methods use conventional techniques so that the fabrication of a semiconductor device containing both optical waveguide structures and copper conductor structures can be made both efficiently and economically.