GERMANIUM SILICON OXYNITRIDE HIGH INDEX FILMS FOR PLANAR WAVEGUIDES

摘要

A composition represented by the formula Si1-xGexO2(1-y)N1.33y, wherein x is from about 0.05 to about 0.6 and y is from about 0.14 to about 0.74 exhibits properties highly suited for use in fabricating waveguides for liquid crysta l based optical devices. In particular, the compositions have an index of refraction of from about 1.6 to about 1.8 for light at a wavelength of 1550 nm, and/or a coefficient of thermal expansion of from about 2.5 x 10-6~C-1 t o about 5.0 x 10-6~C-1. The compositions also have inherently low hydrogen content, and a high hydrogen permeability which allows better hydrogen remov al by thermal annealing to provide a material which exhibits low optical losses and better etching properties than alternative materials.