Smart-cut-like laser slicing of GaN substrate using its own nitrogen

Area of Science:

• Materials Science
• Laser Technology
• Semiconductor Manufacturing

Background:

• Gallium Nitride (GaN) substrates are crucial for high-performance electronic and optoelectronic devices.
• Traditional substrate slicing methods often result in significant material loss (kerf loss) and surface damage.
• Developing advanced dicing techniques for GaN is essential for cost-effective and high-yield manufacturing.

Purpose of the Study:

• To investigate the feasibility of using lasers for slicing Gallium Nitride (GaN) substrates.
• To evaluate the efficiency and precision of laser-based dicing in terms of material loss and damage.
• To assess the suitability of laser-sliced GaN surfaces for subsequent epitaxial growth.

Main Methods:

• Utilized a sub-nanosecond pulsed laser with a wavelength of 532 nm for substrate dicing.
• Employed a laser slicing process designed to minimize kerf loss.
• Characterized the surface and subsurface damage layer resulting from laser processing.
• Performed polishing to remove the damaged layer.
• Grew high-quality homoepitaxial layers on the polished surfaces.

Main Results:

• Successfully demonstrated the slicing of GaN substrates using the specified laser parameters.
• Achieved near-zero kerf loss, significantly reducing material waste compared to conventional methods.
• Quantified the laser-induced damage layer thickness to be approximately 40 µm.
• Confirmed that high-quality homoepitaxial GaN layers can be grown on the polished surfaces, indicating surface integrity recovery.

Conclusions:

• Laser slicing with a 532 nm sub-nanosecond laser is a viable and efficient method for dicing GaN substrates.
• The technique offers significant advantages in reducing material loss and enabling high-quality subsequent epitaxial growth.
• This laser-based approach holds promise for advancing GaN semiconductor manufacturing processes.