Improving the Reliability of Conductive Atomic Force Microscopy
[eng] Owing to its exceptional topographical resolution and electrical sensitivity, Conductive Atomic Force Microscopy (C AFM) has become an essential tool for nanoscale material analysis. However, achieving reproducible data in C AFM remains a challenge, primar ily due to the multitude of factors i...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/211125 |
| Acceso en línea: | https://hdl.handle.net/2445/211125 http://hdl.handle.net/10803/690847 |
| Access Level: | acceso abierto |
| Palabra clave: | Microscòpia de força atòmica Atomic force microscopy |
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Improving the Reliability of Conductive Atomic Force Microscopy |
| title |
Improving the Reliability of Conductive Atomic Force Microscopy |
| spellingShingle |
Improving the Reliability of Conductive Atomic Force Microscopy Weber, Jonas Microscòpia de força atòmica Atomic force microscopy |
| title_short |
Improving the Reliability of Conductive Atomic Force Microscopy |
| title_full |
Improving the Reliability of Conductive Atomic Force Microscopy |
| title_fullStr |
Improving the Reliability of Conductive Atomic Force Microscopy |
| title_full_unstemmed |
Improving the Reliability of Conductive Atomic Force Microscopy |
| title_sort |
Improving the Reliability of Conductive Atomic Force Microscopy |
| dc.creator.none.fl_str_mv |
Weber, Jonas |
| author |
Weber, Jonas |
| author_facet |
Weber, Jonas |
| author_role |
author |
| dc.contributor.none.fl_str_mv |
Lanza, Mario Universitat de Barcelona. Facultat de Física |
| dc.subject.none.fl_str_mv |
Microscòpia de força atòmica Atomic force microscopy |
| topic |
Microscòpia de força atòmica Atomic force microscopy |
| description |
[eng] Owing to its exceptional topographical resolution and electrical sensitivity, Conductive Atomic Force Microscopy (C AFM) has become an essential tool for nanoscale material analysis. However, achieving reproducible data in C AFM remains a challenge, primar ily due to the multitude of factors influencing the stability of the tip sample contact. Among these, tip degradation stands out as a particularly critical issue. To attain high topographical resolution, C AFM probes are designed with small tip radii, but this makes them more susceptible to degradation. Such degradation primarily manifests in two forms. Firstly, since C AFM measurements are commonly performed in contact mode, mechanical abrasion due to lateral frictions. Secondly, exposure to high current d ensities, an inherent consequence of the small tip radii, can lead to partial or complete melting of the probe's conductive coating. While the issue of mechanical abrasion has been mitigated to some extent by performing C AFM measurements in intermittent c ontact mode a recent advancement in the field this thesis concentrates on developing strategies to minimize tip degradation caused by high current densities. To ascertain the current status quo, an in depth analysis of the degradation dynamics of Pt /Ir coated Si probes, currently predominant in C AFM applications, is conducted. In the course of this research, solid Pt probes are examined as a promising alternative. While they exhibit a slightly lower topographical resolution compared to Pt/Ir coated pro bes, their superior endurance through numerous scans and enhanced electrical durability are significant advantages. Beyond utilizing more durable probes, another approach discussed in this thesis is the active limitation of resulting currents, such as thro ugh software based current limitation. This technique allows for extended use of metal coated probes (by approximately a factor of 50, as detailed in Chapter 4.2.1), while also protecting the sample from current induced damage. However, it is noted that so ftware based current limitation does not achieve absolute current limitation. A major contribution of this thesis is the introduction of a novel current limiting sample holder that achieves true current limitation. Unlike software based methods, this holde r restricts currents in both sweep directions through the integration of a MOSFET. This thesis not only deepens our understanding of probe performance in C AFM but also enhances the reliability and cost effectiveness of C AFM studies. Additionally, it open s new avenues for application by providing the ability to precisely control currents during measurements. This is particularly beneficial for analyzing sensitive samples, a need that is becoming increasingly critical with the trend towards smaller device dimensions in recent technology developments. |
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2024 |
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2024 |
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info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/publishedVersion |
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doctoralThesis |
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publishedVersion |
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https://hdl.handle.net/2445/211125 http://hdl.handle.net/10803/690847 |
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https://hdl.handle.net/2445/211125 http://hdl.handle.net/10803/690847 |
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Inglés |
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Inglés |
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(c) Weber, Jonas, 2024 info:eu-repo/semantics/openAccess |
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(c) Weber, Jonas, 2024 |
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openAccess |
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application/pdf |
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Universitat de Barcelona |
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Universitat de Barcelona |
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Tesis Doctorals - Facultat - Física reponame:Dipòsit Digital de la UB instname:Universidad de Barcelona |
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Universidad de Barcelona |
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Dipòsit Digital de la UB |
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Dipòsit Digital de la UB |
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Improving the Reliability of Conductive Atomic Force MicroscopyWeber, JonasMicroscòpia de força atòmicaAtomic force microscopy[eng] Owing to its exceptional topographical resolution and electrical sensitivity, Conductive Atomic Force Microscopy (C AFM) has become an essential tool for nanoscale material analysis. However, achieving reproducible data in C AFM remains a challenge, primar ily due to the multitude of factors influencing the stability of the tip sample contact. Among these, tip degradation stands out as a particularly critical issue. To attain high topographical resolution, C AFM probes are designed with small tip radii, but this makes them more susceptible to degradation. Such degradation primarily manifests in two forms. Firstly, since C AFM measurements are commonly performed in contact mode, mechanical abrasion due to lateral frictions. Secondly, exposure to high current d ensities, an inherent consequence of the small tip radii, can lead to partial or complete melting of the probe's conductive coating. While the issue of mechanical abrasion has been mitigated to some extent by performing C AFM measurements in intermittent c ontact mode a recent advancement in the field this thesis concentrates on developing strategies to minimize tip degradation caused by high current densities. To ascertain the current status quo, an in depth analysis of the degradation dynamics of Pt /Ir coated Si probes, currently predominant in C AFM applications, is conducted. In the course of this research, solid Pt probes are examined as a promising alternative. While they exhibit a slightly lower topographical resolution compared to Pt/Ir coated pro bes, their superior endurance through numerous scans and enhanced electrical durability are significant advantages. Beyond utilizing more durable probes, another approach discussed in this thesis is the active limitation of resulting currents, such as thro ugh software based current limitation. This technique allows for extended use of metal coated probes (by approximately a factor of 50, as detailed in Chapter 4.2.1), while also protecting the sample from current induced damage. However, it is noted that so ftware based current limitation does not achieve absolute current limitation. A major contribution of this thesis is the introduction of a novel current limiting sample holder that achieves true current limitation. Unlike software based methods, this holde r restricts currents in both sweep directions through the integration of a MOSFET. This thesis not only deepens our understanding of probe performance in C AFM but also enhances the reliability and cost effectiveness of C AFM studies. Additionally, it open s new avenues for application by providing the ability to precisely control currents during measurements. This is particularly beneficial for analyzing sensitive samples, a need that is becoming increasingly critical with the trend towards smaller device dimensions in recent technology developments.[cat] Aconseguir dades reproduïbles en C-AFM continua sent un repte, principalment a causa de la multitud de factors que influeixen en l'estabilitat del contacte punta-mostra. Entre aquests, la degradació de les puntes destaca com un tema especialment crític. Per aconseguir una alta resolució topogràfica, les puntes de C-AFM estan dissenyades amb radis molt petits, però això les fa més susceptibles a la degradació. Aquesta degradació es manifesta principalment de dues formes. En primer lloc, com que les mesures amb C-AFM es realitzen habitualment en mode contacte, l’abrasió mecànica causa friccions laterals. En segon lloc, l'exposició a altes densitats de corrent, una conseqüència inherent dels petits radis de punta, pot conduir a la fusió parcial o completa del recobriment conductor de la sonda. Tot i que el problema de l'abrasió mecànica s'ha mitigat fins a cert punt mitjançant la realització de mesures C-AFM en mode de contacte intermitent, un avenç recent en el camp, aquesta tesi se centra a desenvolupar estratègies per minimitzar la degradació de la punta causada per altes densitats de corrent. Per conèixer l'estat actual, realitzo una anàlisi en profunditat de la dinàmica de degradació de les sondes de silici recobertes de platí, que són les més comuns en les aplicacions C-AFM. En el transcurs d'aquesta investigació, examino sondes sòlides de platí com una alternativa prometedora. Més enllà d'utilitzar sondes més duradores, un altre enfocament analitzat en aquesta tesi és la limitació activa dels corrents resultants, com ara mitjançant la limitació de corrent basada en programari. Tanmateix, cal assenyalar que la limitació actual basada en programari no aconsegueix limitar la corrent perfectament. Una contribució important d'aquesta tesi és la introducció d'un nou suport de mostres que aconsegueix limitar la corrent de forma gairebé ideal. Aquesta tesi no només aprofundeix en la nostra comprensió del rendiment de les puntes per a C-AFM, sinó que també millora la fiabilitat de les dades aconseguides mitjançant C-AFM. A més, obre noves vies d'aplicació proporcionant la capacitat de controlar amb precisió els corrents durant les mesures.Universitat de BarcelonaLanza, MarioUniversitat de Barcelona. Facultat de Física2024info:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/211125http://hdl.handle.net/10803/690847Tesis Doctorals - Facultat - Físicareponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglés(c) Weber, Jonas, 2024info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/2111252026-05-27T06:46:51Z |
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