Low loss Si sub 3 N sub 4 - SiO sub 2 optical waveguides on Si.

We have developed an optical integrated circuit waveguide technology based on conventional Si processing. We demonstrate waveguide losses less than 0.3 db/cm in the 1.3 - 1.6micron wavelength range. We use a high refractive index core of Si sub 3 N sub 4 surrounded by SiO sub 2 cladding layers which provides a highly confined optical mode adequate for butt coupling to channel substrates buried heterostructure lasers. We report the first infrared transmission experiments in these waveguides and find two absorption peaks associated with H in SiO sub 2 and Si sub 3 n sub 4 layers at 1.40micron and 1.52micron, respectively. The peak absorptions are 2.2 and 1.2 db/cm, respectively and these peaks can be largely removed by annealing at 11000-1200C.