Scaling to submicron for III-nitride optoelectronic devices: Applications in micro light emitting diodes and resonant tunneling diodes

III-Nitride-based optoelectronic devices have a broad range of applications, from solid state lighting, displays and advanced light sources, to communications and sensing. Micro-LEDs enables next generation displays for virtual and augmented reality, visible light communications, and advanced light sources due to their scalability, high speed, high luminance, and long lifetimes amongst other befits compared to existing technologies. While III-Nitride-based resonant tunneling diodes (RTD) pave way for reliable room temperature THz emitters for security, sensing, imaging, and communications. This thesis first investigates efficiency measurements and demonstrates a method to determine the absolute internal quantum efficiency of LEDs. Structural and optical studies were coupled with a channel-based recombination model to determine the absolute IQE of LEDs. Next, the challenges and development of the fabrication process for sub-micron III-Nitride devices (LEDs and RTDs) are discussed. An electron beam lithography-based fabrication process was developed for mesa formation, oxide opening, and contact metallization/liftoff. Fabrication of electrically injected sub-micron LEDs and RTDs are demonstrated. The properties of the smallest sub-micron top-down fabricated LEDs down to 500 nm is studied. Finally, properties of sub-micron RTDs are studied, demonstrating repeatable negative differential resistance in cubic III-Nitride (AlGaN) based RTDs.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Chiu, Yu-Chieh

Contributors dc:contributor

• Bayram, Can
• Dallesasse, John
• Kim, Kevin
• Lyding, Joseph W
• Basceri, Cem

• micro light-emitting diode
• resonant tunneling diode
• optoelectronic devices
• semiconductor device fabrication

Statement dc:rights

• Copyright 2025 Yu-Chieh Chiu

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129725

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129725