Offset and noise behavior of microfabricated aluminum gallium nitride-gallium nitride two-dimensional electron gas hall-effect sensors
Abstract/Contents
- Abstract
- Magnetic sensors are quite common in everyday life, with a variety of uses in mobile devices, electric machines, cars, motors, navigation, and planetary exploration. They are incredibly useful due to their non-perturbing nature. For example, they infer information about position, velocity, and current in power systems. Silicon Hall-effect sensors are popular for many applications due to their low cost and ease of integration with silicon circuits. However, silicon Hall-effect plates cannot operate at extreme temperatures (below -100 degrees C or above 300 degrees C) due to carrier freeze out or intrinsic carrier leakage, respectively. In addition, Hall-effect plates have challenges with thermal drift, offset, and flicker noise. In this PhD thesis, I start with an in-depth focus on the fabrication of high aspect ratio trenches (18.5:1) in 4H-SiC for potential use in direct hot-spot cooling of GaN-on-SiC power devices as well as extreme environment SiC microelectromechanical system (MEMS) applications. I then switch gears and describe an AlGaN/GaN 2DEG Hall-effect plate with ~100 ppm/K constant-current sensitivity drift, 0.5 micro-Tesla offset, and 200 Hz corner frequency. These metrics surpass state-of-the-art silicon Hall-effect sensors with a larger temperature operation range, stability of sensitivity, and lower offset and noise floor. I then describe the fundamental limits of offset in GaN devices and present an examination of the flicker noise of these devices. Through this work, I have achieved a record-low offset in GaN 2DEG Hall devices, presented the first framework for studying noise in GaN Hall sensors, and have demonstrated a world record aspect ratio in bulk 4H-SiC machining. These contributions will enable a future monolithically integrated GaN-on-SiC platform for extreme environment sensors and power electronics. I conclude with proposing future work, including a path forward for implementing these devices in extreme environment systems.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2019; ©2019 |
| Publication date | 2019; 2019 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Dowling, Karen Marie |
|---|---|
| Degree supervisor | Senesky, Debbie |
| Thesis advisor | Senesky, Debbie |
| Thesis advisor | Howe, Roger Thomas |
| Thesis advisor | Plummer, James D |
| Degree committee member | Howe, Roger Thomas |
| Degree committee member | Plummer, James D |
| Associated with | Stanford University, Department of Electrical Engineering. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Karen Marie Dowling. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2019. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2019 by Karen Marie Dowling
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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