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  imec-ePIXfab SiPhotonics: iSiPP50G


Basic characteristics

As shown in Figure 1, the imec-ePIXfab SiPhotonics full platform technology consists of:

  • Substrate: SOI with 220nm Si, 2um buried oxide
  • WG module (WaveGuide): 220nm full Si etch for strip waveguides, photonic crystals, etc.
  • FC module (FiberCoupler): 70nm partial Si etch for fiber couplers, rib waveguides, etc.
  • SK module (Socket): 150nm partial Si etch
  • Poly-Si module: extra etch-level for efficient fiber couplers
  • 4 P and N-type doping levels for electro-optic modulator design and heaters for thermo-optic modulation
  • Ge photodiodes as detectors
  • High speed Ge electro-absorption modulators
  • 2 levels of metal interconnect
  • Edge coupler

Figure 1: Schematic Cross section of the SiPhotonics full platform technology


The prototypes are produced in imec's 200mm wafer fab with statistical process control of all tools/ chambers.
The process is based on 0.13um mask technology (WG, FC, SK), and 193nm DUV lithography,
optimized for generic photonics applications.

Module Specification
Substrate 220nm SOI
SOI patterning 3 etch depth levels
Minimum line and space: 150nm
Poly-Si Deposition and patterning
Doping 4-level N and P
Germanium Photodiodes, electro-absorption modulators
Contacts W contact plugs on silicide
M1, VIA and M2 Standard CMOS metallization
Bondpads Standard AlCu bondpads
BEOL openings Edge couplers

Indicative performance

Minimum width of lines and spacings is 150nm. Device performance as shown in the table.
Components are targeted for 1550nm wavelength? Few components for 1310nm (fiber coupler,
waveguide, Ge PD) are available as well.
Note that the table is subject of continuous update; it may change without prior notice.

  Device Specification  
  Strip waveguide (WG) Loss 2.5dB/cm  
  Deep rib waveguide (SK) Loss 2.0dB/cm  
  Shallow rib waveguide (FC) Loss 1.5dB/cm  
  Basic fiber coupler TE (FC) Insertion loss 5.5dB  
    Peak wavelength 1550nm  
    1dB bandwidth 30nm  
  Advanced fiber coupler TE (RFC) Insertion loss 2.5dB  
    Peak wavelength 1550nm  
    1dB bandwidth 30nm  
  50:50 splitter Insertion loss <0.5dB  
    Imbalance <5%  
  50:50 2x2 coupler Insertion loss <0.5dB  
    Imbalance <5%  
    Phase accuracy <5%  
  Waveguide crossing Loss 0.3dB  
    Crosstalk <-30dB  
  Ge photodiode low-speed OE bandwidth @ -1V > 1GHz  
    Responsivity @ 1550nm, -1V 0.7A/W  
    Dark current @ -1V, 20°C < 50nA  
  Ge photodiode medium-speed OE bandwidth @ -1V 20GHz  
    Responsivity @ 1550nm, -1V 0.6A/W  
    Dark current @ -1V, 20°C < 50nA  
  Ge photodiode high-speed OE bandwidth @ -1V > 50GHz  
    Responsivity @ 1550nm, -1V 0.5A/W  
    Dark current @ -1V, 20°C < 50nA  
  Travelling wave MZI modulator EO bandwidth @ -2.0V 11GHz  
    Length 1.5mm  
    Insertion loss 5.0dB  
    Vpi @ -2V 8.5V  


SiPhotonics designers target a wide range of applications:

  • Datacom and short-reach optical interconnect
  • Telecom and access networks
  • Sensors (gas, pressure, strain) and read-out ICs
  • Biomedical: biomolecule detection, drug development, point-of-care diagnostics




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