A Simple Yet Powerful Architecture

G-ray Disruptive Potential is a combination of advanced proprietary technologies for absorber fabrication and monolithic integration:

  • LEPECVD equipment for Si-Ge epitaxy on large area CMOS processed silicon wafers
  • Si-Ge epitaxy on CMOS processed silicon wafers
  • Low temperature wafer-to-wafer bonding enabling direct conversion
  • Two layers monolithic integration (no bump bonding; no middle TSVs)

Pushing the actual limits of imaging frontiers, our latenium™ detector relies on a :

  • X-Ray Absorber – SiGe Epitaxy on Si Wafer
  • Seamless Bonded Interface
  • Electronics

Intellectual Property

To protect this proprietary disruptive technologies, three Patent Groups have already been filed

Monolithic CMOS integrated pixel detector

Photon Counting CBCT

System and methods to allow charge collection across bonded interfaces

X-Ray Absorber – Si-Ge Epitaxy on Si Wafer

It is a combination of materials that define the sensitivity of the absorption layers.

Seamless Bonded Interface

Low temperature direct wafer-to-wafer bonding process

G-ray with equipment from EV Group can bond (glue together) two silicon wafers with just a very thin amorphous interfacial region.

Direct wafer-to-wafer bonding of sensor wafer and readout wafer is a low temperature direct bonding technology without the need of any special high-temperature metallization layers.

Bump bonding for hybrid pixels remains a dominant cost for detectors. Our Direct Bonding process offers a very significant manufacturing costs reduction and new application opportunities.

Enabling features

  • New sensor materials: higher sensitivity, large area detection
  • Direct conversion: high-speed readout, single photon counting, energy discrimination
  • Two-layer monolithic concept (no bump bonding; no middle TSVs): lower noise, higher bandwith and higher gain due to lower capacitive load;
  • Backside-illumination: 100 percent fill factor; smaller die/pixel size, better resolution, faster speed, better signal-to-noise ratio

Electronics

  • Pixel Array Detector: direct conversion + single photon counting
  • Smart electronics for signal processing, storage and post-processing.
  • Typical Performance Measures
    • Charge collection efficiency (CCE)
    • Sensitivity (Electron-Hole Pair Creation Energy)
    • Detective Quantum Efficiency (DQE)
    • Modulation transfer function (MTF)
    • Large area deposition ability

Manufacturing Equipment

In addition, G-ray has developed its own manufacturing equipment for SiGe epitaxial growth and for low temperature wafer-to-wafer bonding.

Under construction, it is expected to be functional from the end of Q2 2017.