Studies of Gallium Nitride based Schottky Barrier Diodes and Light Emitting Diodes
- Mo, Chen
- [University Park, Pennsylvania] : Pennsylvania State University, 2022.
- Physical Description:
- 1 electronic document
- Additional Creators:
- Chu, Rongming
- etda.libraries.psu.edu , Connect to this object online.
- Restrictions on Access:
- Restricted (PSU Only).
- The surface roughness and nitrogen deficiencies caused by inductively coupling plasma etching have been major problems in manufacturing GaN based electronic and photonic devices. The surface of Gallium Nitride needs recovery treatment after plasma etching. In my research of Schottky Barrier Diodes, the above-mentioned problems were addressed by developing a novel KOH-etching approach to remove the surface residues. Based on the analysis of current density to voltage curve, KOH solution treatment helps to remove the etch-damaged layer and flattening the surface morphology. The sample with KOH solution has lower surface density, shorter defect region thickness and higher barrier, and all of which will reduce the leakage current with several orders of magnitude. In my research of GaN based Micro LEDs, the sidewall of the mesa is protected by a layer of SiO2 with atomic layer deposition (ALD) after ICP etching. We analyzed that the passivation layer helps to deactivate surface traps and reduce leakage current in forward bias. According to the simulation results and the light-current-voltage measurements, the sidewall passivation layer grown by atomic layer deposition reduces the Schottky Reed Hall non-radiative recombination rate, thereby increasing the external quantum efficiency. From the experimental results, the improvement of the pixel's quantum efficiency at 150K is significantly higher than that at 300K. Shockley-Read-Hall nonradiative recombination rate decreases rapidly at low temperature due to longer carrier lifetime and increased difficulty of electron and hole recombination in traps. From the modeling results, the circular shaped pixels have better performance than square shaped pixels due to the following reasons: (1) the sharp corners have more surface roughness and defects during fabrication (2) the circular shaped pixel has better current spreading.
- Other Subject(s):
- Dissertation Note:
- Ph.D. Pennsylvania State University 2022.
- Technical Details:
- The full text of the dissertation is available as an Adobe Acrobat .pdf file ; Adobe Acrobat Reader required to view the file.
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