Dislocation Filter Based on LT-GaAs Layers for Monolithic GaAs/Si Integration

Area of Science:

• Materials Science
• Semiconductor Physics
• Epitaxy

Background:

• Heteroepitaxial growth of Gallium Arsenide (GaAs) on Silicon (Si) is crucial for integrating optoelectronic devices.
• Dislocations in GaAs/Si heterostructures degrade device performance.

Purpose of the Study:

• Investigate low-temperature (LT) GaAs layers as dislocation filters in GaAs/Si heterostructures.
• Evaluate the impact of intermediate LT-GaAs layers and annealing on structural properties.
• Assess the suitability of fabricated heterostructures for light-emitting devices.

Main Methods:

• Utilized low-temperature (LT) Gallium Arsenide (GaAs) layers as intermediate buffer layers.
• Applied post-growth and cyclic in situ annealing techniques.
• Characterized structural properties including dislocation density, surface roughness, and non-radiative recombination centers.

Main Results:

• Reduced threading dislocation density to 5 × 10^6 cm^-2.
• Achieved root-mean-square surface roughness of 1.1 nm.
• Lowered non-radiative recombination centers to levels comparable to homoepitaxial GaAs.

Conclusions:

• LT-GaAs layers combined with cyclic annealing significantly enhance GaAs/Si heterostructure quality.
• Elastic deformations and gallium vacancies in LT-GaAs contribute to improved structural properties.
• The developed GaAs/Si heterostructures are suitable for high-quality light-emitting devices with self-assembled quantum dots.