Laser slice thinning of GaN-on-GaN high electron mobility transistors

Area of Science:

• Materials Science
• Semiconductor Processing
• Optoelectronics

Background:

• Gallium Nitride (GaN) substrates are expensive, driving the need for cost-effective processing techniques.
• Previous work demonstrated laser slicing for GaN substrates, enabling reuse but not device fabrication applicability.
• High-electron-mobility transistors (HEMTs) are crucial semiconductor devices often fabricated on GaN substrates.

Purpose of the Study:

• To investigate the applicability of laser slicing as a device fabrication process for GaN-on-GaN HEMTs.
• To demonstrate the thinning of HEMTs using laser slicing without compromising device integrity or performance.
• To explore the potential of laser slicing for creating ultra-thin semiconductor devices and reducing GaN substrate consumption.

Main Methods:

• Demonstrated thinning of GaN-on-GaN HEMTs using a laser slicing technique.
• Applied laser slicing after the completion of the HEMT fabrication process.
• Evaluated the structural integrity (fracture) and electrical characteristics of laser-thinned HEMTs.

Main Results:

• Successful thinning of HEMTs to 50 µm thickness using laser slicing.
• No significant fracture was observed in the laser-sliced HEMT devices.
• No adverse effects of laser-induced damage on the electrical characteristics of the HEMTs were detected.
• Demonstrated the feasibility of applying laser slicing post-device fabrication.

Conclusions:

• Laser slicing is a viable technique for thinning GaN-on-GaN HEMTs, even after fabrication.
• The process preserves device integrity and electrical performance, offering a new method for semiconductor fabrication.
• This technique significantly reduces GaN substrate consumption, paving the way for ultra-thin devices (10 µm thickness).