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Design and Fabrication of High Performance Ultra-Wide Bandgap AlGaN Devices

Razzak, Towhidur
http://orcid.org/0000-0001-9232-7024
http://rave.ohiolink.edu/etdc/view?acc_num=osu1619031091410235

Abstract Details

2021, Doctor of Philosophy, Ohio State University, Electrical and Computer Engineering.
Ultra-wide bandgap III-Nitride materials, such as AlxGa1-xN, possess many desirable material properties and have been shown to be suitable for a wide range of RF and power applications. These materials possess high electron saturation velocity and extremely high breakdown electric fields. The combination of these two properties makes them ideal for power density scaling at microwave and mm-wave frequencies. Due to the high critical breakdown electric fields in these devices, it is possible to fabricate ultra-scaled devices with these materials as well, which is important for both RF and power devices. Scaling for RF devices helps to significantly boost the electron saturation velocity but maintaining a high electric field profile, which can significantly cut down on the carrier transit time. For power devices, scaling is also important, as the miniaturization of the power circuitry is critically dependent of smaller and more efficient devices. In addition, the large critical breakdown field of these materials could enable more favorable device characteristics for normally-off devices used in power switching applications. It is critical to investigate AlGaN-based devices for high frequency and high-power applications as the necessity for long-range communications at higher frequencies are becoming a necessity. This thesis discusses into the fabrication, analysis and characterization of ultra-wide bandgap AlxGa1-xN channel devices using heterostructure engineered contact layers aimed at improving contact resistance to these devices. Two different approaches to contact formation to metal organic chemical vapor deposition (MOCVD) grown high Al-composition AlGaN films are discussed. Using this approach state of the art device results are also reported. Novel approaches to electric field management in ultra-wide bandgap nitrides have also been explored in this work. Integration of extreme dielectric constant materials like BaTiO3 as an effective solution to electric field management in lateral devices has been demonstrated which led to the observation of the highest average breakdown field for a semiconductor device to date.
Siddharth Rajan (Advisor)
Wu Lu (Committee Member)
Anant Agarwal (Committee Member)
176 p.
Electrical Engineering; Physics
AlGaN channel, AlGaN, GaN, Ultrawide Bandgap, UWBG, Transistors, high breakdown, contact resistance

Recommended Citations

Citations

  • Razzak, T. (2021). Design and Fabrication of High Performance Ultra-Wide Bandgap AlGaN Devices [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1619031091410235

    APA Style (7th edition)

  • Razzak, Towhidur. Design and Fabrication of High Performance Ultra-Wide Bandgap AlGaN Devices . 2021. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1619031091410235.

    MLA Style (8th edition)

  • Razzak, Towhidur. "Design and Fabrication of High Performance Ultra-Wide Bandgap AlGaN Devices ." Doctoral dissertation, Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1619031091410235

    Chicago Manual of Style (17th edition)

osu1619031091410235
619
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This open access ETD is published by The Ohio State University and OhioLINK.