Universität zu Köln

Wölk, Dorothea ORCID: 0000-0003-1595-1610 (2024). Neutron Induced Single-Event-Effects in Gallium-Nitride High Electron Mobility Transistors. PhD thesis, Universität zu Köln.

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Abstract

This work is focused on the study of radiation-induced, especially neutron induced, single event effects in normally off gallium nitride high electron mobility transistors (GaN HEMTs). Normally off gallium nitride high power transistors have been commercially available on the market for a short number of years. Due to a large bandgap between conduction and valence band, this semiconductor material is inherently more resistant to failure due to induced charge carriers. In particular, the sensitivity to charge introduced by single particles has thus far only been investigated briefly. The knowledge about the reliability of the devices against radiation effects is important to ensure the reliability and functionality for safetyrelevant applications in space as well as on Earth. At this point in time, no protocols for testing GAN HEMTs on radiation hardness and single event effects have been published. In this study, three commercially available gallium nitride high electron mobility transistors of different device designs were investigated and compared with respect to their sensitivity to single event effects caused by radiation, especially neutrons. For this purpose, the devices under test were irradiated with the same assembly using five different types of particles and measured online. Irradiation was performed using high-energy xenon ions, ultra-high-energy lead ions, high-energy protons, monoenergetic neutrons and neutrons whose energy is similar to the atmospheric spectrum. The devices were irradiated with drain voltage applied but blocked and for each measured device the leakage current between drain and source as well as gate and source were recorded, likewise failures of the devices due to short circuit were registered. From the measurement data it was possible to determine the failure rate and the cross section for Single Event Effects due to particle ion interactions. Furthermore, the dependence of the failure rate on the energy deposition in the material and the comparability of proton and monoenergetic neutron measurements with the failure rate due to atmospheric neutrons were investigated. By observing gate and drain leakage current, two different failure mechanisms could be observed. In this work, no failures below 60% of the nominal drain voltage and 50% of the measured breakdown voltage of the devices were observed. Summarized and interpreted in the context of previous measurements, no inherent radiation hardness of the investigated gallium nitride high electron mobility transistors over comparable silicon or silicon carbide transistors could be shown for single particle effects.

Item Type:	Thesis (PhD thesis)
Translated title:	Title Language Neutronen induzierte Einzelteilchen Effekte in Gallium-Nitrid Transistoren mit hoher Elektronenbeweglichkeit German
Creators:	Creators Email ORCID ORCID Put Code Wölk, Dorothea dwoelk@posteo.de orcid.org/0000-0003-1595-1610 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-725202
Date:	2024
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Physics > Institute for Nuclear Physics
Subjects:	Generalities, Science Natural sciences and mathematics Physics Technology (Applied sciences)
Uncontrolled Keywords:	Keywords Language Single Event Effects English Neutrons UNSPECIFIED GaN-HEMT UNSPECIFIED
Date of oral exam:	5 March 2024
Referee:	Name Academic Title Dewald, Alfred Prof. Dr. Michely, Thomas Prof. Dr.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/72520