Photon-Trapping Microstructure for InGaAs/Si Avalanche Photodiodes Operating at 1.31 μm

Area of Science:

• Optoelectronics
• Semiconductor Devices
• Photonics

Background:

• Avalanche photodiodes (APDs) are critical for photo-communication due to high quantum efficiency, low power consumption, and small size.
• Monolithic integration of optical components and signal processing on silicon substrates is key for cost reduction and performance enhancement in APDs.
• InGaAs/Si APDs are significant for integrated silicon photonics.

Purpose of the Study:

• To enhance the performance of InGaAs/Si APDs using a photon-trapping (PT) structure.
• To investigate the impact of the PT structure on absorption efficiency and responsivity.
• To propose an optimized InGaAs/Si PT-APD design based on optical and electrical simulations.

Main Methods:

• Demonstration of a photon-trapping (PT) structure in an InGaAs/Si APD on an SOI substrate.
• Optical and electrical simulations to analyze device performance.
• Comparison of the proposed PT-APD with the original InGaAs/Si APD.

Main Results:

• The InGaAs/Si PT-APD exhibits very high absorption efficiency at 1310 nm wavelength with an 800 nm absorption layer.
• The optimized InGaAs/Si PT-APD shows improved performance and higher responsivity compared to the original design.
• The PT structure effectively enhances light absorption within the thin InGaAs layer.

Conclusions:

• The photon-trapping structure is a viable method for significantly improving InGaAs/Si APD performance.
• The developed InGaAs/Si PT-APD is a promising candidate for next-generation photo-communication systems.
• Further optimization of the PT-APD design can lead to even greater advancements in optoelectronic devices.