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TECHNOLOGY

Our unique approach, called BackSide-on-BOX, enables seamless and extensive integration of active and passive optical components by combining Si and InP/III-V materials.

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Unprocessed InP/III-V dies are bonded on the backside of processed Silicon-On-Insulators (SOI) wafers, only where it is needed. Our fabrication process is CMOS-compatible and relies on the standard silicon-photonics process. Our optical component library includes lasers (WDM laser arrays & tunable lasers), modulators, SOA, waveguides, wavelength filters, surface fiber couplers, and photodetectors. 

 
Fabrication Steps
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    1- SiPho

    Processing

    The SiP wafer is fabricated according to standard SiP processes available in commercial foundries on an SOI wafer comprising the original Si substrate, the Buried OXide (BOX) layer, and the top Si layer.

     

    The top Si layer is etched for defining the Si waveguides and other optical elements such as modulators, multiplexers, and demultiplexers.

     

    Ge PDs can be formed by using epitaxial deposited Ge, and SiNx can be added to form low-loss, high-performance passive devices.

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    2 - Molecular 

    Bonding 

    The SiP-processed wafer is then flip-bonded onto a Si handle.

     

    The original Si substrate is removed, leaving the BOX layer on top. 

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    The InP dies with laser gain epitaxial layers are bonded onto the exposed BOX layer wherever a laser source, amplifier or modulator is required.

     

    The bonding step does not require any precise alignment as the epitaxial layers are not processed yet.

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    3 - III-V material patterning

    InP or GaAs die substrates are removed to leave only the gain epi-layers on the BOX.

     

    Finally, the gain layers are etched at the wafer level to define the lasers’ waveguides.

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    4 - Electrical

    Contacts

    Electrical contacts are then made on the III-V devices as well as on the SiP components, using materials and processes of CMOS-compatible foundries.

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    At the end of the manufacturing flow, there is a chemical mechanical planarization to enable the integration with electronic ICs (Driver and TIA).

     

    The latter can be flip chip assembled on the PIC surface according to standard packaging technology.

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Benefits

PERFORMANCE

AND 

RELIABILITY

  • ​High-coupling efficiency of lasers in the waveguide

  • No alignment of lasers needed

  • Optical amplification on-chip

  • High-speed modulator with low insertion loss

  • Intrinsic hermetic design

FEATURE-RICH

IN A COMPACT FORM FACTOR

  • All-optical components in one-chip, including lasers

  • Germanium (Ge) for efficient photodetector

  • Silicon Nitride (SiNx) for improved passive devices 

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COST OPTIMISED 

FOR VOLUME

  • Production in commercial foundry â€‹

  • Wafer-level lasers integration & test 

  • Flip-chip assembly for Electronic IC

  • No hermetic package needed

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Publications

1.

Back-Side-on-BOX Heterogeneous Laser Integration for Fully Integrated Photonic Circuits on Silicon

CONTACT US

SCINTIL Photonics

BHT – Bât. 52  

7, parvis Louis Néel – CS 20050  

38040 Grenoble cedex 09

France

  

©2021 by SCINTIL Photonics.