@phdthesis{d6c53a0abbfd46a4b15d32fead4b6a40,
title = "Interface Modification and Characterization of Nanostructured Semiconductors: A Bridge to Contemporary Electronics",
abstract = "This research presents advancements into the fabrication, operation and characterization of electronicnanomaterials and devices. It focuses on the interfaces of metals, oxides and semiconductors anddeveloping techniques to improve their integration into devices. Covering nanoelectronics fromphotovoltaics to circuit elements, a combined suite of scanning probe and X-ray techniques was usedto provide insight into structural and electronic properties.Scanning probe techniques such as piezoresponse force microscopy corroborated the formation ofultrathin ferroelectric hafnia films. A unique Kelvin probe force microscopy method for nondestructivelymeasuring directly on nanowire arrays complemented electron beam induced current in theinvestigation of photovoltaic p-n junctions. Temperature- and time-dependent photoluminescencespectroscopy was used show how nitrogen plasma treatment could increase GaAs nanowire solar cellefficiency, while photoelectron spectroscopy demonstrated surface conversion to GaN and long-termpassivation.X-ray radiation from synchrotrons such as MAX IV enabled the probing of novel circuit components. Xrayabsorption spectroscopy helped to explain reactive sputtering of TiN, connecting electrode texturingwith device endurance and remanent polarization. Photoemission spectroscopy was integral tounderstanding the impact of device fabrication on thin film behavior. For resistive random-accessmemory, it controverted conventional wisdom by showing that interlayer oxidation protected key devicefunctionality. In ferroelectric devices it proved the opposite, highlighting the necessity for shorttimescale thermal processes to limit film decomposition. Finally, operando hard X-ray photoelectronspectroscopy was employed to follow ferroelectric switching in real time. Synchrotron compatibledevices were developed, and characterization of buried interfaces revealed a polarization dependent,reversible redox between HZO and InAs which, if left unchecked, ultimately leads to breakdown.Generally, this work confirms that, independent of the specific material and device application, it iscrucial to have a large characterization toolbox at hand, especially one that includes surface-sensitivetechniques tailored for operando measurements at the micro- and nanoscale.",
keywords = "III-V, XPS, AFM, electronics, hafnium oxide, Photovoltaics",
author = "Austin Irish",
note = "Defence details Date: 2024-10-18 Time: 13:15 Place: Rydbergsalen, Department of Physics. Join via zoom: https://lu-se.zoom.us/j/67139588544 External reviewer(s) Name: Hinkle, Christopher Title: Professor Affiliation: University of Notre Dame. --- ",
year = "2024",
month = sep,
day = "23",
language = "English",
isbn = "978-91-8039-980-7",
publisher = "Lund University",
type = "Doctoral Thesis (compilation)",
school = "Lund University",
}