Title :
Comparison among various Si3N4 waveguide geometries grown within a CMOS fabrication pilot line
Author :
Daldosso, Nicola ; Melchiorri, Mirko ; Riboli, Francesco ; Girardini, Manuel ; Pucker, Georg ; Crivellari, Michele ; Bellutti, Pierluigi ; Lui, Alberto ; Pavesi, Lorenzo
Author_Institution :
Dept. of Phys., Univ. of Trento, Italy
fDate :
7/1/2004 12:00:00 AM
Abstract :
Low-pressure chemical-vapor deposition (LPCVD) thin-film Si3N4 waveguides have been fabricated on Si substrate within a complementary metal-oxide-semiconductor (CMOS) fabrication pilot line. Three kinds of geometries (channel, rib, and strip-loaded) have been simulated, fabricated, and optically characterized in order to optimize waveguide performances. The number and optical confinement factors of guided optical modes have been simulated, taking into account sidewall effects caused by the etching processes, which have been studied by scanning electron microscopy. Optical guided modes have been observed with a mode analyzer and compared with simulation expectations to confirm the process parameters. Propagation loss measurements at 780 and 632.8 nm have been performed by both using the cutback technique and measuring the drop of intensity of the top scattered light along the length of the waveguide. Loss coefficients of approximately 0.1 dB/cm have been obtained for channel waveguides. These data are very promising in view of the development of Si-integrated photonics.
Keywords :
chemical vapour deposition; etching; integrated optics; optical fabrication; optical losses; optical waveguides; rib waveguides; scanning electron microscopy; silicon compounds; 632.8 nm; 780 nm; CMOS fabrication pilot line; Si; Si-Si3N4; Si-integrated photonics; Si3N4 waveguide geometries; channel geometry; channel waveguides; complementary metal-oxide-semiconductor; cutback technique; etching process; guided optical modes; loss coefficients; low-pressure chemical-vapor deposition; mode analyzer; optical characterization; optical confinement factors; optical guided modes; propagation loss measurements; rib geometry; scanning electron microscopy; sidewall effects; strip-loaded geometry; thin-film Si3N4 waveguides; top scattered light; Chemicals; Electron optics; Length measurement; Loss measurement; Optical microscopy; Optical scattering; Optical waveguides; Semiconductor thin films; Sputtering; Substrates; -compatible technology; CMOS; Complementary metal–oxide–semiconductor; optical mode analysis; optical propagation losses; silicon nitride; silicon-integrated photonics; waveguides;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2004.831182
