Make it different!

Glass on Silicon technology is implemented at INPHOTEC in order to:


  • Cover the full range of Photonic Integrated applications
  • Extend the wavelength range from visible up to 1600nm and achieve very wide transparency range
  • Guarantee very low propagation losses


At INPHOTEC the facilities can process 6’’ wafers for glass on silicon integration, through LPCVD stoichiometric Si3N4 for high contrast dielectric materials, depositions of SiO2: Ge doped and SiOxNy for low medium contrast by PECVD anneal deposition.

The choice of the waveguide material will be defined by customer design based on

requested specs in terms of wavelength of signal and integration density.

The edge roughness and low stress structures will be achieved through “helicon source plasma system” advanced etching system.

Upper cladding solutions for high aspect ratio structures with low stress materials will be achieved by processing thick glass layer by PECVD liquid source with Semicon standard precursors.


The process capabilities available at Fondazione INPHOTEC is reported in the table:


Material Δ RI* Waveguide Size Curvature
SiO2 (Ge) 0.7% 4.5X4.5 µm2 7 mm
SiO2 (Ge) 2.5% 2.5X2.5 µm2 1.2 mm
SiON 7% 2.2X2.2 µm2 300 µm
Si3N4 35% submicron 7 µm


*Δ RI= n2core-n2clad/2 n2core

The line can support development and medium level productions, the key equipment available for this platform are:

  • Etching system by Omega-Mori with C4F8 – CH2F2 gas mixture
  • Si3N4 and Si Poly vertical and horizontal by LPCVD
  • UV exposure system front and backside alignment
  • PECVD liquid system by TEOS and BTEOS a PTEOS for high conformal coating
  • PECVD high rate deposition for < Ge doped layer
  • Evaporation system for metal layer by lift-off
  • Field Emission SEM Microscope low acceleration voltage
  • Spectro ellipsometer for high accuracy determination of n, k and film thickness