Nucleation-Accelerated Epitaxy at Large-Area (100) β‑Ga₂O₃ Terraces

Area of Science:

• Materials Science
• Crystal Growth
• Semiconductor Epitaxy

Background:

• Epitaxy requires surface steps for efficient adatom incorporation.
• Monoclinic gallium oxide (β-Ga₂O₃) homoepitaxy on (100) substrates is challenging due to flat terraces and low step density.

Purpose of the Study:

• To develop a method to increase step density on (100) β-Ga₂O₃ substrates.
• To enhance the growth rate and quality of β-Ga₂O₃ homoepitaxy.

Main Methods:

• A self-organized annealing process was used to subdivide terraces.
• Substep-templated substrates were utilized for subsequent homoepitaxial growth.

Main Results:

• Annealing created substeps of approximately half the unit cell height.
• Achieved a high growth rate of ~2.83 μm h^-1 for (100) β-Ga₂O₃ homoepitaxy.
• Maintained reasonable structural quality and electronic functionality.

Conclusions:

• Substep templating is a viable strategy to enhance β-Ga₂O₃ homoepitaxy.
• This approach overcomes limitations of high surface-energy planes and off-axis miscuts.
• The method offers a practical route for improving β-Ga₂O₃ for advanced device applications.