Patent ID: 6670210
Filing Date: 2003-12-30
Classification: G02B

Abstract:
A method of fabricating an optical waveguide, the method comprising:(a) coating a substrate with a cladding material comprising SiO2 and Si3N4 by a PECVD process using SiH4, N2O and a nitrogen-containing gas selected from NH3 and N2 as precursor gases fed to a chamber housing the substrate and with a first nitrogen-containing gas flow rate, (b) coating a layer of core material on the cladding using the PECVD process with SiH4, N2O and the nitrogen-containing gas selected from NH3 and N2 as precursor gases but at a second nitrogen-containing gas flow rate that is less than the first nitrogen-containing gas flow rate, (c) coating a cladding material layer on the layer of core material using the PECVD process using SiH4, N2O and the nitrogen-containing gas selected from NH3 and N2 as precursor gases but at a third nitrogen-containing gas flow rate that is greater than the second nitrogen-containing gas flow rate, (d) repeating steps (b) and (c) to produce alternating layers of cladding material and core material, (e) etching the alternating layers of core material and cladding material to from an optical waveguide core, (f) coating the optical waveguide core with cladding material.