Date of Graduation
Doctor of Philosophy in Engineering (PhD)
Aluminum Nitride;GaN Integrated Circuit (IC) technology;high-voltage;III-Nitride semiconductors;molecular beam epitaxy;wide bandgap semiconductors
III-Nitride (III-N) semiconductors with wide bandgap (WBG) characteristics offer promising advancements for high power density, high voltage, and high-frequency applications, presenting a promising alternative to traditional silicon (Si) technology. However, native substrate material for the majority of WBG semiconductors is still not commercially affordable. Because of its highly mature progression, utilizing standard Si wafers as substrates is a cost-effective alternative. This dissertation explores the development of electronic devices based on III-N thin films, grown monolithically via molecular beam epitaxy (MBE), followed by several processing techniques. Initially, a heterojunction p-n diode is realized, incorporating the growth of single-crystal WBG AlN films on a Si(111) surface. This AlN layer, with a breakdown voltage exceeding a ten-fold that of Si, serves as an effective blocking layer, offering potential device thickness savings. Further, the initial stages of a GaN-based current limiter device and a GaN-based charge pump circuit are investigated. With MBE-grown GaN thin films and precise etching processes, substantial improvements are anticipated in the activation time of the current limiter, potentially reaching mere microseconds, which would constitute a marked improvement compared to existing technology. In terms of the charge pump circuit, an AlN capacitor and High Electron Mobility Transistors (HEMTs) have been integrated on a single chip, setting the groundwork for intricate GaN layer etching in the development of a proof-of-concept for GaN Integrated Circuit (IC) technology. Although these GaN-based devices are yet to undergo full electrical characterization, the preliminary material growth and characterization have provided valuable insights for their future development. This research underscores the potential of III-N semiconductors in the creation of next-generation electronic devices, and sets the stage for further advances in affordable, high-performance WBG technology.
Allaparthi, R. (2023). Integrated and Monolithic III-Nitride Devices Grown by MBE. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/4826
Available for download on Saturday, August 30, 2025