Performance of GaN vertical light emitting diodes using wafer bonding process with Al-alloyed graphite substrate

Area of Science:

• Materials Science
• Semiconductor Devices
• Optoelectronics

Background:

• Vertical-structure light emitting diodes (VLEDs) are crucial for modern lighting and displays.
• Current fabrication methods face challenges with wafer cracking and reliability.
• Laser lift-off (LLO) is a key technique in VLED manufacturing.

Purpose of the Study:

• To investigate the use of Al-alloyed graphite as a supporter in VLED fabrication using wafer bonding.
• To compare the performance and reliability of VLEDs fabricated with Al-alloyed graphite supporters versus Si supporters and Cu plating.
• To assess the suitability of Al-alloyed graphite for wafer bonding processes in VLEDs.

Main Methods:

• Fabrication of VLEDs using wafer bonding with Al-alloyed graphite and Si supporters.
• Application of laser lift-off (LLO) techniques.
• Comparison of VLED performance (output power, forward voltage) and reliability with those fabricated by Cu plating.

Main Results:

• VLEDs with Al-alloyed graphite supporters exhibited no cracks during LLO, unlike those with Si supporters.
• The output power of wafer-bonded VLEDs with Al-alloyed graphite was comparable to Cu-plated VLEDs.
• Forward voltage was higher for wafer-bonded VLEDs compared to Cu-plated ones.
• Wafer bonding demonstrated superior reliability compared to Cu plating.

Conclusions:

• Al-alloyed graphite is a promising supporter material for wafer bonding in VLED fabrication, preventing cracks during LLO.
• The wafer bonding method using Al-alloyed graphite offers comparable output power and improved reliability over Cu plating.
• This study highlights Al-alloyed graphite as a viable alternative for VLED supporter materials.