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GeSn/Ge Technology-Material Growth, Engineered Substrate and Devices
The Near-Infrared (NIR) and Mid-Infrared (MIR) range has attracted much research interest because of its practical applications in optical sensing, imaging and communications. Group IV photonic integrated circuits (PICs) have drawn attraction for such applications with cost-effectiveness, low power consumption, ultra-compact device footprint, and complementary metal-oxide-semiconductor (CMOS) compatibility.
Our technology provides the solutions for the above applications from material growth, such as epitaxial GeSn/Ge films, black Si (b-Si); engineered substrate, such as Ge-on-insulator (GOI), GeSn-on-insulator (GSOI), flexible nanomembrane; and device fabrication such as photodetector.
For material growth:
- The epitaxial growth of GeSn films with Sn content varying from 4 to 11% using digermanium (Ge2H6) and tin chloride (SnCl4) as precursors in a commercial Chemical Vapor Deposition (CVD) system under reduced pressure condition have been achieved;
- Black Si with an ultra-low light reflectance has been achieved with GeX (metal) thin alloy assisted etching process.
For engineered substrate:
- GOI and GSOI substrates have been fabricated through direct wafer bonding (DWB) which involves the development of chemical and mechanical polishing (CMP) process;
- Flexible nanomembranes have been achieved and are better shaped and adapted to different substrates.
For devices fabrication:
Photodetectors with various techniques have been achieved for enhancing the performances such as detectivity, responsivity, low dark current density and so on.
Technology Features, Specifications and Advantages
The epitaxial GeSn films with various Sn contents could be utilized for different applications operating in different wavelength ranges, from NIR to MIR. The single crystal GeSn films have a Sn content varied from 4% to 11%. GeX (metal) assisted b-Si has been achieved through dry etching without any mask.
Various engineered substrates such as GOI, GSOI have been fabricated through DWB with perfect bonding interface and enhanced optical confinement. Flexible nanomembranes open the room for the increasing demands required for next-generation optoelectronics with light-weight design, better portability, excellent implantability, large-area compatibility, as well as seamless heterogeneous integration.
Beside the material growth and substrate engineering, this technology offer provides a photodetector, which is one of the key building optical devices for integrated photonics, with various techniques for the performance enhancements. Low dark current, high optical responsivity, and considerable detectivity have been achieved. Techniques that involved in the above performance enhancements include defects management via O2/O3 annealing/oxidation, resonance optical cavity, photo-trapping design and surface plasmon treatment.
- Optical communication
- Wireless communication
- Molecular sensing
- 3D imaging
- Night vision
- Remote sensing
- Environmental monitoring
- Solar energy
- Photocatalytic water splitting
- Light detection and ranging (LiDAR) system
- LiFi receiver
- Molecular or gas sensor
- Analog light signal receiver
- Optical power receiver
- Active-pixel sensor
- Solar cell
The fabrication techniques and processes offered in this technology are CMOS-compatible and promising for large scale production with low manufacturing cost. The b-Si in our technology could enhance the efficiency of the commercial Si solar cells (>2%). The flexible nanomembrane developed in the technology could provide the platform for flexible wearable photodetector fabrication to enable numerous emerging applications. Our photodetectors can be used in the above-mentioned applications, such as LiDAR system, which is one of the promising remote sensors for autonomous vehicles and the molecular sensing which could help in preventing the environmental hazards. This technology offer would greatly impact our economies communities, health, and related industries.