10 Gbps silicon waveguide-integrated infrared avalanche photodiode

Area of Science:

• Optoelectronics
• Semiconductor devices
• Photonics

Background:

• High-speed photodiodes are crucial for optical communication systems.
• Silicon photonics offers a cost-effective platform for integrated optoelectronics.
• Existing silicon avalanche photodiodes often face limitations in speed and compatibility.

Purpose of the Study:

• To fabricate monolithic silicon avalanche photodiodes (APDs) compatible with CMOS processes.
• To achieve high-speed operation (10 Gbps) at a telecommunication wavelength (1550 nm).
• To integrate APDs with silicon-on-insulator (SOI) rib waveguides for enhanced performance.

Main Methods:

• Fabrication of p-i-n junction APDs using CMOS-compatible processes.
• Integration of the photodiode with an SOI rib waveguide.
• Introduction of deep levels in the silicon bandgap via ion implantation and annealing to enhance photo-generation.
• Characterization of device performance, including bandwidth and eye pattern.

Main Results:

• Demonstrated monolithic silicon APDs operating at 10 Gbps and 1550 nm.
• Achieved a small signal 3 dB bandwidth of 2.0 GHz.
• Observed an open eye pattern at 10 Gbps, indicating good signal integrity.
• Measured a responsivity of 4.7 ± 0.5 A/W for a 600 µm device at 40 V reverse bias.

Conclusions:

• CMOS-compatible silicon APDs integrated with SOI rib waveguides can achieve high-speed operation.
• The developed photodiodes are suitable for high-performance optical communication applications.
• This work advances silicon photonics for integrated optoelectronic transceivers.