Study on different isolation technology on the performance of blue micro-LEDs array applications
Shao-Hua Lin1, Yu-Yun Lo2, Yu-Hsuan Hsu2
1Institute of Electrics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan, ROC.
Discover Nano
|June 13, 2024
Summary
This study optimized blue micro-light-emitting diodes (LEDs) using arsenic implantation for electrical isolation. Deeper implantation enhanced light output power and external quantum efficiency but slightly increased efficiency droop.
Area of Science:
- Solid State Physics
- Materials Science
- Optoelectronics
Background:
- Micro-light-emitting diodes (LEDs) are crucial for advanced display and lighting technologies.
- Efficient electrical isolation is essential for high-performance micro-LED arrays.
- Traditional mesa etching can be problematic for small-scale device fabrication.
Purpose of the Study:
- To investigate the effects of arsenic multi-energy ion implantation as an alternative to mesa etching for electrical isolation in blue micro-LEDs.
- To analyze the impact of varying ion implantation depths and profiles on the electrical and optical properties of micro-LEDs.
- To optimize the fabrication process for improved light output power and external quantum efficiency.
Main Methods:
- Fabrication of a 3×3 blue micro-LED array (10×10 μm² pixel size, 15 μm pitch) on a sapphire substrate using metalorganic chemical vapor deposition (MOCVD).
- Utilized photolithography, etching, E-beam evaporation, and multi-energy arsenic ion implantation for device fabrication and isolation.
- Systematically varied arsenic implantation depth and energy to create different depth profiles.
Main Results:
- Arsenic implantation effectively replaced mesa etching for electrical isolation, with implantation depth correlating to average energy.
- Increased implantation depth led to higher light output power and peak external quantum efficiency, improving from 5.33% to 9.82%.
- Deeper implantation also resulted in a slight increase in efficiency droop (from 46.3% to 48.6%) and potential damage to the n-GaN layer, increasing series resistance.
Conclusions:
- Multi-energy arsenic ion implantation is a viable method for electrical isolation in blue micro-LED fabrication, offering improved efficiency.
- Careful control of implantation depth and energy is necessary to balance efficiency gains with potential drawbacks like increased series resistance and droop.
- Further research can focus on mitigating n-GaN damage and reducing efficiency droop for even better micro-LED performance.
