High performance waveguide uni-travelling carrier photodiode grown by solid source molecular beam epitaxy

Area of Science:

• Optoelectronics
• Semiconductor Device Fabrication
• Materials Science

Background:

• Metal Organic Vapour Phase Epitaxy (MOVPE) and Gas Source MBE (GSMBE) are traditional methods for InGaAsP materials.
• These methods have limitations, including zinc diffusion (MOVPE) and handling toxic gases (GSMBE).
• Uni-traveling-carrier photodiodes (UTC-PDs) are crucial for high-speed optical communication.

Purpose of the Study:

• To report the first waveguide-coupled phosphide-based UTC-PDs grown by Solid Source Molecular Beam Epitaxy (SSMBE).
• To demonstrate the advantages of SSMBE over MOVPE and GSMBE for UTC-PD fabrication.
• To characterize the performance of these novel UTC-PDs and their integration with antennas and optical fibers.

Main Methods:

• Growth of phosphide-based UTC-PDs using Solid Source Molecular Beam Epitaxy (SSMBE).
• Integration of UTC-PDs with Coplanar Waveguides (CPW).
• 3D full-wave electromagnetic modeling for antenna-integrated UTCs and optical coupling analysis.

Main Results:

• Achieved UTC-PDs with a 3 dB bandwidth exceeding 65 GHz.
• Demonstrated output RF power of 1.1 dBm at 100 GHz.
• Accurate prediction of radiated power from 200 GHz to 260 GHz using 3D modeling.
• First optical 3D full-wave modeling of waveguide UTCs, detailing fiber coupling.

Conclusions:

• SSMBE is a viable and advantageous technique for fabricating high-performance phosphide-based UTC-PDs.
• The developed UTC-PDs exhibit excellent high-frequency performance and potential for terahertz applications.
• 3D modeling provides accurate predictions and detailed insights into device performance and integration.