Laser-assisted local metal-organic vapor phase epitaxy

Area of Science:

• Materials Science
• Semiconductor Physics
• Chemical Engineering

Background:

• Selective area epitaxial growth is crucial for device integration and defect reduction in heteroepitaxy.
• Conventional methods using masking or surface structuring are limited by integral substrate heating and thermal budget constraints.
• Laser heating offers a localized thermal solution for epitaxial growth.

Purpose of the Study:

• To present a novel epitaxial growth approach using localized laser heating combined with metal-organic precursors.
• To demonstrate maskless, selective area growth of III-V compound semiconductors.
• To analyze the design principles and performance of this laser-assisted local MOVPE technique.

Main Methods:

• Utilizing a laser source for localized heating of the substrate.
• Employing metal-organic precursors for pyrolithic chemical reactions (MOVPE).
• Implementing surface de-oxidation prior to growth and controlling reactor pressure and temperature gradients.

Main Results:

• Achieved maskless, local epitaxial growth of III-V compound semiconductor layers on a 50-1500 µm scale with high structural and optical quality.
• Demonstrated linear growth rates between 0.5-9 µm/h.
• Identified conditions for smooth island surfaces (de-oxidation) and step-flow growth modes (temperature gradient control).

Conclusions:

• Laser-assisted local MOVPE is a viable technique for selective area epitaxial growth without masks or surface structuring.
• The method overcomes thermal budget limitations associated with conventional substrate heating.
• Further research can optimize growth parameters for specific applications and materials like GaAs.