Winkler, Robert (2024)
Structure-Property-Correlations in HfO₂ based Memristive Devices.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00027736
Ph.D. Thesis, Primary publication, Publisher's Version
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Item Type: | Ph.D. Thesis | ||||
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Type of entry: | Primary publication | ||||
Title: | Structure-Property-Correlations in HfO₂ based Memristive Devices | ||||
Language: | English | ||||
Referees: | Molina-Luna, Prof. Dr. Leopoldo ; Alff, Prof. Dr. Lambert | ||||
Date: | 13 September 2024 | ||||
Place of Publication: | Darmstadt | ||||
Collation: | 148 Seiten in verschiedenen Zählungen | ||||
Date of oral examination: | 9 July 2024 | ||||
DOI: | 10.26083/tuprints-00027736 | ||||
Abstract: | This PhD research aimed to bridge information gaps in oxide electronics through synthesis, macroscopic and microscopic investigation, and device characterization. Utilizing Reactive Molecular Beam Epitaxy (RMBE) and other Physical Vapor Deposition (PVD) techniques, the study precisely fabricated high-quality semiconductor heterostructures. It focused on the development and impact of texture in thin films, particularly in memristive systems with metal-insulator-metal (MIM) structures. Initial investigations involved 23 nm TiN₁₋ₓ thin films grown on c-cut sapphire, revealing a biaxial texture and elongated grain structure influenced by substrate miscut. Notably, TiN₁₋ₓ films with high nitrogen deficiency exhibited grain boundary dissociation, advantageous for memristive devices as an ohmic bottom electrode. Subsequent work engineered textures in HfO₂ thin films, used as the insulating layer in MIM structures. Elevated temperature RMBE growth allowed the development of distinct (001) or (111) textures on (111) textured TiN₁₋ₓ, impacting device performance. Density functional theory (DFT) calculations linked grain boundary atomic structure to the observed variations in forming voltage (VF). Additionally, the microstructure evolution of amorphous HfO₂ during in situ transmission electron microscopy (TEM) and 4D-scanning TEM (4D-STEM) annealing was studied. Crystallization into the monoclinic phase at 180 °C was observed, with texture development enhancing device performance by lowering the forming voltage from -6.1 V to -4.2 V. |
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Status: | Publisher's Version | ||||
URN: | urn:nbn:de:tuda-tuprints-277360 | ||||
Classification DDC: | 500 Science and mathematics > 500 Science | ||||
Divisions: | 11 Department of Materials and Earth Sciences > Material Science > Advanced Electron Microscopy (aem) | ||||
Date Deposited: | 13 Sep 2024 12:05 | ||||
Last Modified: | 16 Sep 2024 06:24 | ||||
URI: | https://tuprints.ulb.tu-darmstadt.de/id/eprint/27736 | ||||
PPN: | 521518571 | ||||
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