Integration of InP membranes with embedded InGaAs quantum wells on silicon-on-insulator by tunnel epitaxy

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Integration of III-V semiconductors with silicon photonics is crucial for on-chip optical gain.
• Silicon-on-insulator (SOI) platforms enable dense photonic integrated circuits.

Purpose of the Study:

• To investigate the materials properties of InP membranes with embedded InGaAs multi-quantum wells (MQWs) grown on SOI via tunnel epitaxy.
• To understand the facet-dependent growth and composition of InGaAs MQWs.
• To guide the design of efficient active regions for silicon-coupled InP membrane lasers.

Main Methods:

• Cross-sectional scanning transmission electron microscopy (STEM) with differential phase contrast (DPC) imaging.
• Energy-dispersive X-ray spectroscopy (EDX) for elemental analysis.
• Atomic-column-based strain analysis to assess material quality and composition.

Main Results:

• High-quality InP membranes were achieved with defects localized to the V-groove region.
• Facet-dependent InGaAs MQW formation was observed on (111)A, (110), and (111)B facets.
• High-indium ( >80% In), compressively strained (110) quantum wells were confirmed with no misfit dislocations.
• Ultra-thin quantum wells showed higher indium incorporation than bulk InGaAs.

Conclusions:

• Tunnel epitaxy enables high-quality InP membrane growth on SOI.
• Facet engineering is key for controlling InGaAs MQW composition and strain.
• These findings are vital for developing advanced, electrically injected InP membrane lasers on SOI for silicon photonics.