InAlN/GaN high electron mobility transistors for Venus surface exploration
- Historical and proposed missions to the surface of Venus have been severely limited in both scope and duration by the lack of robust microelectronics that can operate within Venus' extreme environment. Traditional silicon technology cannot survive on Venus without the use of expensive and bulky active cooling measures due to the scalding surface temperature of 465°C. To address this technological gap and enable extended duration robotic surface exploration on Venus, I propose the use of wide-bandgap gallium nitride (GaN) technology for uncooled microelectronics (e.g., sensors, micromechanical resonators, transistors). In this thesis, I present original research on the design and microfabrication of InAlN/GaN high electron mobility transistors (HEMTs), which leverage a two-dimensional electron gas (2DEG) conducting channel and can provide sensing, power, and telecommunications for a Venus lander or rover. I explore the use of several Schottky gate electrode materials that are attractive candidates for reliable high-temperature operation. The experimental results from electrically characterizing HEMTs utilizing these gate materials up to 600°C in air for durations of up to 6 days are presented. I then analyze Schottky barrier properties and make recommendations for engineering superior Schottky contacts. The electrical operation of HEMTs exposed to simulated Venus surface conditions (465°C, > 90 bar, supercritical CO2 ambient) for up to 10 days is presented. Finally, I present the first every demonstration of an uncooled GaN device successfully operating in situ simulated Venus surface conditions. The in situ experiment concluded after 5 days and 21 hours of device operation, which is a 70-fold greater duration than the 2 hour record operating length of silicon-based microelectronics used on the Venera 13 mission. As a whole, these contributing proof-of-concept experiments support the use of the InAlN/GaN HEMT platform and provide a road map for further maturing this technology for uncooled microelectronics.
|Type of resource
|electronic resource; remote; computer; online resource
|1 online resource.
|Eisner, Savannah Ryann
|Degree committee member
|Degree committee member
|Stanford University, Department of Electrical Engineering
|Statement of responsibility
|Savannah Ryann Benbrook Eisner.
|Submitted to the Department of Electrical Engineering.
|Thesis Ph.D. Stanford University 2022.
- © 2022 by Savannah Ryann Eisner
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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