Kinetic study of hydrogen lateral diffusion at high temperature in a directly-bonded InP-SiO₂/Si substrate

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Hybrid integration of III-V materials on silicon is crucial for advanced photonic integrated circuits.
• Current methods lack post-bonding epitaxial regrowth capabilities, unlike mature III-V on III-V technologies.
• This limits the complexity and performance of silicon photonics devices.

Purpose of the Study:

• To investigate the material behavior of InP on silicon (InPoSi) under metal-organic vapor phase epitaxy (MOVPE) regrowth conditions.
• To understand and overcome void formation during high-temperature processing.
• To demonstrate a viable method for growing complex heterostructures on InPoSi templates.

Main Methods:

• Studied InP membrane on silicon (InPoSi) behavior during MOVPE.
• Analyzed void formation at elevated temperatures (400 °C and above).
• Investigated hydrogen diffusion kinetics and implemented outgassing trenches.

Main Results:

• Observed void formation at 400 °C in InP seed layers on silicon, attributed to hydrogen diffusion weakening the bonding interface.
• Quantified hydrogen lateral diffusion length.
• Demonstrated effective void suppression using outgassing trenches.
• Successfully grew high-quality AlGaInAs-based multi-quantum well (MQW) heterostructures on InPoSi.

Conclusions:

• Outgassing trenches are essential for enabling high-temperature MOVPE regrowth on InPoSi by mitigating void formation.
• This approach is compatible with MOVPE conditions (650 °C) and standard photonic fabrication processes.
• Paves the way for advanced, complex III-V/Si photonic integrated devices.