The most commonly known macro scale probing devices are simply comprised of metallic leads used for measuring electrical signals. On the other hand, micromachined probing devices are realized using microfabrication techniques and are capable of providing very fine, micro/nano scale interaction with matter; along with a broad range of applications made possible by incorporating MEMS sensing and actuation techniques. Micromachined probes consist of a well-defined tip structure that determines the interaction space, and a transduction mechanism that could be used for sensing a change, imparting external stimuli or manipulating matter. Several micromachined probes intended for biological and nanotechnology applications were fabricated, characterized and tested. Probes were developed under two major categories. The first category consists of Micro Electromagnetic Probes for biological applications such as single cell, particle, droplet manipulation and neuron stimulation applications; whereas the second category targets novel Scanning Probe topologies suitable for direct nanopatterning, variable resolution scanning probe/dip-pen nanolithography, and biomechanics applications. The functionality and versatility of micromachined probes for a broad range of micro and nanotechnology applications is successfully demonstrated throughout the five different probes/applications that were studied. It is believed that, the unique advantages of precise positioning capability, confinement of interaction as determined by the probe tip geometry, and special sensor/actuator mechanisms incorporated through MEMS technologies will render micromachined probes as indispensable tools for microsystems and nanotechnology studies.

The initiation and high resolution control of surface confined chemical reactions would be both beneficial for nanofabrication and fundamentally interesting. In this work, spatially controlled scanning probe directed organometallic coupling, patterned functional protein immobilisation and highly localised reversible redox reactions on SAMs were investigated. Catalytically active palladium nanoparticles were mounted on a scanning probe and an appropriate reagent SAM was scanned in a reagent solution. This instigated a spatially resolved organometallic coupling reaction between the solution and SAM-phase reagents. Within this catalytic nanolithography a spatial resolution of ~10nm is possible, equating to zeptomole-scale reaction. The methodology was applied to reactions such as Sonogashira coupling and local oligo(phenylene vinylene) synthesis. By altering the experimental protocols, relating probe scan velocity to reaction yield and characterising the nanopattern, a PVP matrix model describing a proposed mechanism of catalytic nanolithography, was presented. Though ultimately limited by probe deactivation, calculations indicated that activity per immobilised nanoparticle is very high in this configuration. For biopatterning, surface nanopatterns defined by carboxylic functionality were generated from methyl-terminated SAMs by local anodic oxidation (LAO) initiated by a conductive AFM probe. By employing suitable linker compounds, avidin and Stefin-A quadruple Mutant (SQM) receptive peptide aptamers were patterned at sub-100nm resolution. The multiplexed sensing capability of an SQM array was demonstrated by reacting generated patterns with single or a mixture of multiple antibodies. The reversible redox conversion and switching of reactivity of hydroquinone-terminated SAMs was electrochemically demonstrated prior to an application in redox nanolithography. In this methodology, spatially controlled probe-induced in situ "writing" and "erasing" based on reversible redox conversion were conducted on hydroquinone terminated SAM. In combination with dip-pen nanolithography, a novel method of redox electro-pen nanolithography was designed and the method’s application for lithography was examined.

Im Laufe der Verkleinerungen integrierter Schaltungen ergab sich die Notwendigkeit der alternativen dielektrischen Materialen. Hohe Polarisierbarkeiten in diesen dielektrischen Dünnfilmen treten erst in hoch direktionalen kristallinen Phasen auf. Aufgrund der erschwerten Integrierbarkeit von epitaktischen, einkristallinen Oxidfilmen können nur poly-, beziehungsweise nanokristalle Filme eingesetzt werden. Diese sind jedoch mit hohen Leckströmen behaftet. Weil die Information in einer DRAM-Zelle als Ladung in einem Kondensator gespeichert wird ist der Verlust dieser Ladung durch Leckströme die Ursache für Informationsverluste. Die Frequenz der notwendigen Auffrischungszyklen einer DRAM-Zelle wird direkt durch die Leckströme bestimmt. Voraussetzungen für die Entwicklung neuer dielektrischer Materialien ist das Verständnis der zugrunde liegenden Ladungsträgertransportmechanismen und ein Verständnis der strukturellen Schichteigenschaften, welche zu diesen Leckströmen führen. Conductive atomic force Microscopy ist ein Rastersondenmethode mit der strukturelle Eigenschaften mit lokaler elektrischer Leitfähigkeit korreliert wird. Mit dieser Methode wurde in einer vergleichenden Studie die räumlichen Leckstromverteilungen untersucht. Und es wurde gezeigt, dass es genügt eine nicht geschlossene Zwischenschicht Aluminiumoxid in eine Zirkoniumdioxidschicht zu integrieren um die Leckströme signifikant zu reduzieren während eine ausreichend hohe Kapazität erhalten bleibt. Darüberhinaus wurde ein CAFM modifiziert und benutzt um das Schaltverhalten eines Siliziumnanodrahtschottkybarrierenfeleffektransistor in Abhängigkeit der Spitzenposition zu untersuchen. Es konnte experimentell bestätigt werden das die Schottkybarrieren den Ladungstransport in diesen Bauteilen kontrollieren. Darüber hinaus wurde ein proof-of-concept für eine umprogrammierbaren nichtflüchtigen Speicher, der auf Ladungsakkumulation und der resultierenden Bandverbiegung an den Schottkybarrieren basiert, gezeigt. / In the course of the ongoing downscaling of integrated circuits the need for alternative dielectric materials has arisen. The polarizability of these dielectric thin-films is highest in highly directional crystalline phases. Since epitaxial single crystalline oxide films are very difficult to integrate into the complex DRAM fabrication process, poly- or nanocrystalline thin-films must be used. However these films are prone to very high leakage currents. Since the information is stored as charge on a capacitor in the DRAM cell, the loss of this charge through leakage currents is the origin of information loss. The rate of the necessary refresh cycles is directly determined by these leakage currents. A fundamental understanding of the underlying charge carrier transport mechanisms and an understanding of the structural film properties leading to such leakage currents are essential to the development of new, dielectric thin-film materials. Conductive Atomic Force Microscopy (CAFM) is a scanning probe based technique which correlates structural film properties with local electrical conductivity. This method was used to examine the spatial distribution of leakage currents in a comparative study. I was shown that it is sufficient to include an unclosed interlayer of Aluminium oxide into a Zirconium dioxide film to significantly reduce leakage currents while maintaining a sufficiently high capacitance. Moreover, a CAFM was modified and used to examine the switching behavior of a silicon nanowire Schottky barrier field effect transistors in dependence of the probe position. It was proven experimentally that Schottky barriers control the charge carrier transport in these devices. In addition, a proof of concept for a reprogrammable nonvolatile memory device based on charge accumulation and band bending at the Schottky barriers was shown.

Face à la quête constante de miniaturisation, les nanosciences ont connu un essor fulgurant lors de la dernière décennie. Au sein de ces dernières, les procédés lithographiques – clé de voûte de l’industrie des semi-conducteurs – permettent désormais d’accéder à des nanomatériaux fonctionnels. Malgré les récents développements technologiques, l’obtention de nanostructures possédant une résolution inférieure à 100 nm reste un défi majeur pour la communauté scientifique.Devant l’intérêt grandissant de développer des méthodes alternatives en nanolithographie, notre groupe s’est tourné vers une approche chimique, nommée nanolithographie par sonde locale catalytique (cSPL). Combinant la robustesse de la catalyse organométallique et la flexibilité offerte par la microscopie à sonde locale, notre stratégie permet la nanostructuration de surfaces organominérales par la création de liaisons covalentes dans des conditions douces. Cette approche innovante constitue le premier exemple d’immobilisation d’un catalyseur homogène à la surface d’une pointe d’un microscope à force atomique (AFM), dans l’optique de contrôler spatialement une réactivité chimique, l’époxydation localisée d’alcènes terminaux. Ces fonctions époxydes ont été employées comme points d’ancrage dans la nanostructuration à façon de surfaces de silicium avec une large variété de nucléophiles. De plus, l’optimisation des paramètres physico-chimique influant sur la réaction, a permis d’atteindre des résolutions latérales de l’ordre de 40 nm et laisse entrevoir de nombreuses perspectives dans la nanostructuration tridimensionnelle de matériaux organiques. / In regard to the constant quest for miniaturization, the field of nanosciences has known a tremendous expansion over the last decade. More precisely, lithographic technologies - key processes for the semi-conductor industry – allow to access to functional nanomaterials. Despite recent technological developments, the synthesis of nanostructures with a sub-100 nm resolution remains a major challenge for the scientific community.Due to the growing interest in the design of new nanolithographic methods, our group has focused its efforts on the development of a chemical approach, named catalytic scanning probe lithography (cSPL). Unifying the robustness of organometallic catalysis and the flexibility offered by scanning probe microscopy, our strategy allows the nanostructuration of organomineral surfaces in a soft controlled manner by the formation of covalent bonds. This innovative approach represents the first example of the immobilization of an homogeneous catalyst on the edge of an atomic force microscope (AFM) tip, in order to spatially control a chemical reaction: the localized epoxidation reaction of terminal alkenes. Those epoxides were then used as anchoring sites, in the nanostructuration of silicon wafers with a broad range of nucleophiles. Moreover, the different physico-chemical parameters influencing the reaction were optimized, allowing us to reach lateral resolutions down to 40 nm and opening new perspectives in the field of 3D-nanostructuration of organic materials.

Organic molecules such as porphyrins and alkanethiols are currently being investigated for applications such as sensors, light-emitting diodes and single electron transistors. Porphyrins are stable, highly conjugated compounds and the choice of metal ion and substituents bound to the macrocycle as well as other effects such as chemical surrounding and cluster size modulate the electronic and photonic properties of the molecule. Porphyrins and their derivatives are relatively non-toxic and their very rich photo- and electro-chemistry, and small HOMO-LUMO gaps make them outstanding candidates for use in molecularly-enhanced electronic applications. For these studies, self-assembled tri-pyridyl porphyrin thiol derivatives have been fully characterized on Au(111) surfaces. A variety of surface characterization techniques such as Atomic Force Microscopy (AFM), Scanning Tunneling Microscopy (STM), FT-IR spectroscopy and X-ray photoelectron spectroscopy (XPS) have been implemented in order to obtain information regarding the attachment orientation based on the angle and physical height of the molecule, conductivity which is determined based on the apparent height and current-voltage (I-V) measurements of the molecule, conductance switching behavior due to conformational or other effects as well as the stability of the molecular ensembles. Specifically, the transport properties of free base and zinc coordinated tri-pyridyl porphyrin thiol molecular islands inserted into a dodecanethiol matrix on Au(111) were investigated using STM and cross-wire inelastic electron tunneling spectroscopy (IETS). The zinc porphyrin thiol islands observed by STM exhibited reversible bias induced switching at high surface coverage due to the formation of Coulomb islands of ca. 10 nm diameter driven by porphyrin aggregation. Low temperature measurements (~ 4 K) from crossed-wire junctions verified the appearance of a Coulomb staircase and blockade which was not observed for single molecules of this compound or for the analogous free base. Scanning probe lithography via nanografting has been implemented to directly assemble nanoscale patterns of zinc porphyrin thiols and 16-mercapotohexadecanoic acid on Au surfaces. Matrix effects during nanopatterning including solvent and background SAMs have been investigated and ultimately ~ 10 nm islands of zinc porphyrins have been fabricated which is the optimal size for the observed switching effect.

Das Ziel dieser Arbeit ist die optische Untersuchung von ferroelektrischen Domänen und Domänenwänden auf lokaler Skala. Dafür wurden neuartige nichtinvasive Ansätze entwickelt, die auf der Anwendung optischer Rastersondenmikroskopie basieren. Die untersuchten Schlüsseleigenschaften umfassen den elektrooptischen Effekt für verschiedene Domänenorientierungen und die Brechungindexänderungen an Domänenwänden an Bariumtitanat-Einkristallen. Die lokale Messung der elektrooptischen Eigenschaften wurde mit räumlich stark begrenzten elektrischen Feldern durchgeführt, die mittels elektrisch leitfähigen Spitzen angelegt wurden. Dieser experimentelle Ansatz erlaubt nicht nur die Messung verschiedener elektrooptischer Koeffzienten, sondern auch die Unterscheidung von allen auftretenden, auch antiparallelen, Domänenausrichtungen. Durch Anlegen eines zusätzlichen elektrischen Feldes mittels der gleichen Spitze konnte auch das ferroelektrische Schalten mit dieser optischen Methode untersucht werden. Die Experimente wurden durch eine numerische Modellierung der elektrischen Feldverteilung und der resultierenden elektrooptischen Antwort begleitet. Die Ergebnisse der Modellierung sind dabei in sehr guter Übereinstimmung mit den experimentellen Ergebnissen. Dies erlaubt auch die Trennung von Beiträgen verschiedener elektrooptischer Koeffzienten und den entsprechenden Feldkomponenten. ür die experimentelle Untersuchung von den theoretisch vorhergesagten Brechungsindexprofilen einzelner Domänenwände, wurde die Sensitivität der optischen Sonde auf lokale Änderungen des Brechungsindex mittels Polarisations- und Positionsmodulation erhöht. Obwohl die Abbildung einer einzelnen Domänenwand nicht gelang, konnte damit zumindest eine obere Grenze für den optischen Effekt einer Domänenwand experimentell gewonnen werden, welche verträglich mit den theoretischen Vorhersagen ist. / The goal of this thesis is the optical investigation of ferroelectric domains and domain walls at the very local scale. For that, novel noninvasive approaches based on optical scanning probe microscopy are developed. The key properties investigated are the electrooptic effect for different domain orientations and refractive-index changes at single domain walls of barium titanate single crystals. The local probing of the electro-optic response is performed with strongly confined electric fields, applied via a conductive tip. With this approach we can not only probe different electro-optic coeffcients, but also identify all occurring domain orientations, even antiparallel ones. The application of additional bias fields by the same tip is used to investigate ferroelectric switching and domain growth by optical means. The experiments are supported by numerical modelling of the electric-field distribution and the resulting electro-optic response. The modelling shows excellent agreement with the measurements, and allows us to separate the contributions of different electro-optic coeffcients and their associated electric-field components. For the experimental observation of the theoretically predicted refractive-index profiles at single ferroelectric domain walls, polarization and position modulation of the optical probe is used to obtain high sensitivity to local modifications of the refractive index. An upper limit to the optical effect to the optical effect of a single domain wall is deduced from the experiment, which is compatible with the effect predicted by theory.

This critical review summarizes recent developments in the fabrication of patterned polymer brushes. As top-down lithography reaches the length scale of a single macromolecule, the combination with the bottom-up synthesis of polymer brushes by surface-initiated polymerization becomes one main avenue to design new materials for nanotechnology. Recent developments in surface-initiated polymerizations are highlighted along with diverse strategies to create patterned polymer brushes on all length scales based on irradiation (photo- and interference lithography, electron-beam lithography), mechanical contact (scanning probe lithography, soft lithography, nanoimprinting lithography) and on surface forces (capillary force lithography, colloidal lithography, Langmuir–Blodgett lithography) (116 references). / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

For the past decades, Kelvin probe force microscopy (KPFM) developed from a sidebranch of atomic force microscopy to a widely used standard technique. It allows to measure electrostatic potentials on any type of sample material with an unprecedented spatial resolution. While the technical aspects of the method are well understood, the interpretation of measured data remains object of intense research. This thesis intends to prove an advanced view on how sample systems which are typical for ultrahigh resolution imaging, such as organic molecular submonolayers on metals, can be quantitavily analysed with the differential charge density model. In the first part a brief introduction into the Kelvin probe experiment and atomic force microscopy is given. A short review of the theoretical background of the technique is presented. Following, the differential charge density model is introduced, which is used to further explain the origin of contrast in Kelvin probe force microscopy. Physical effects, which cause the occurence of local differential charge densities, are reviewed for several sample systems that are of interest in high resolution atomic force microscopy. Experimental evidence for these effects is presented in the second part. Atomic force microscopy was used for in situ studies of a variety of sample systems ranging from pristine metal surfaces over monolayer organic adsorbates on metals to ferroelectric substrates both, with and without organic thin film coverage. As the result from these studies, it is shown that the differential charge density model accurately describes the experimentally observed potential contrasts. This implies an inherent disparity of the measurement results between the different Kelvin probe force microscopy techniques; a point which had been overseen so far in the discussion of experimental data. Especially for the case of laterally strong confined differential charge densities, the results show the opportunity as well as the necessity to explain experimental data with a combination of ab initio calculations of the differential charge density and an electrostatic model of the tip-sample interaction.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16851号 / 工博第3572号 / 新制||工||1540(附属図書館) / 29526 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 杉村 博之, 教授 酒井 明, 准教授 鈴木 基史 / 学位規則第4条第1項該当

Disertační práce se zabývá studiem povrchových vlastností jedno a vícevrstvých filmů deponovaných z vinyltriethoxysilanových a tetravinylsilanových monomerů. Zabývá se také charakterizací adheze jednovrstvých filmů z tetravinylsilanu. Plazmaticky polymerizované tenké vrstvy byly připraveny na leštěných křemíkových substrátech pomocí plazmové depozice z plynné fáze za ustálených podmínek. Povrchové vlastnosti vrstev byly charakterizovány pomocí různých metod rastrovací sondové mikroskopie a nanoindentačních technik jako je konvenční a cyklická nanoindentace. Vrypový test byl použit pro charakterizaci vlastností adheze vrstev. Jednovrstvé filmy připravené za různých depozičních podmínek byly charakterizovány s ohledem na povrchové morfologie a mechanické vlastností (modul pružnosti, tvrdost). Výsledky morfologie povrchu, analýzy zrn, nanoindentace, analýzy konečných prvků a modulů mapování pomohly rozlišit hybridní charakter filmů, které byly deponovány při vyšších výkonech RF-výboje. Nový přístup byl použit v povrchové charakterizaci vícevrstvého filmu pomocí rastrovací sondové mikroskopie a nanoindentace. Adhezívní chování plazmaticky polymerizovaných vrstev různých mechanických vlastností a tloušťek bylo analyzováno pomocí normálních a laterálních síl, koeficientu tření, a snímků vrypů získaných pomocí mikroskopie atomárních sil.