No description available.

As the semiconductor technology roadmap further extends, the development of next generation silicon systems becomes critically challenged. On the one hand, design and manufacturing closures become much more difficult due to the widening gap between the increasing integration density and the limited manufacturing capability. As a result, manufacturability issues become more and more critically challenged in the design of reliable silicon systems. On the other hand, the continuous scaling of feature size imposes critical issues on traditional interconnect materials (Cu/Low-K dielectrics) due to power, delay and bandwidth concerns. As a result, multiple classes of new materials are under research and development for future generation technologies. In this dissertation, we investigate several critical Computer-Aided Design (CAD) challenges under advanced nanolithography and nanophotonics technologies. In addressing these challenges, we propose systematic CAD methodologies and optimization techniques to assist the design of high-yield and high-performance integrated circuits (IC) with low power consumption. In Very Large Scale Integration (VLSI) CAD for nanolithography, we study the manufacturing variability under resolution enhancement techniques (RETs) and explore two important topics: (1) fast and high fidelity lithography hotspot detection; (2) generic and efficient manufacturability aware physical design. For the first topic, we propose a number of CAD optimization and integration techniques to achieve the following goals in detecting lithography hotspots: (a) high hotspot detection accuracy; (b) low false-positive rate (hotspot false-alarms); (c) good capability to trade-off between detection accuracy and false-alarms; (d) fast CPU run-time; and (e) excellent layout coverage and computation scalability as design gets more complex. For the second topic, we explore the routing stage by incorporating post-RET manufacturability models into the mathematical formulation of a detailed router to achieve: (a) significantly reduced lithography-unfriendly patterns; (b) small CPU run-time overhead; and (c) formulation generality and compatibility to all types of RETs and evoling manufacturing conditions. In VLSI CAD for nanophotonics, we focus on three topics: (1) characterization and evaluation of standard on-chip nanophotonics devices; (2) low power planar routing for on-chip opto-electrically interconnected systems; (3) power-efficient and thermal-reliable design of nanophotonics Wavelength Division Multiplexing for ultra-high bandwidth on-chip communication. With simulations and experiments, we demonstrate the critical role and effectiveness of Computer-Aided Design techniques as the semiconductor industry marches forward in the deeper sub-micron (45nm and below) domain. / text

A oxidação anódica local utilizando o Microscópio de Força Atômica (AFM - Atomic Force Microscopy) foi investigada aplicando-se uma tensão negativa entre sonda de nitreto de silício e superfícies de Si. Todas as amostras foram limpas em uma solução de 1 NH4OH (30%): 1H2O2 (38%): 4H2O(DI) a 80ºC conhecida na literatura como SC1 (Standard Cleaning 1) ou, alternativamente, uma imersão em solução diluída de ácido hidrofluorídrico seguido de SC1 ou fervura em álcool isopropílico. As nano-oxidações consistiram de padrões quadrados localizados de óxido com área de 0,25 µm² e foram obtidos através do crescimento de linhas paralelas com espaço e comprimento interlinear constante (<2 nm) e várias varreduras dos quadrados em uma mesma área. Das análises de AFM, foram obtidos perfis transversais e 3D, os quais foram empregados na obtenção da espessura do óxido como função da tensão aplicada, número de varreduras e intervalo de tempo após a limpeza SC1. Foi observado que a espessura aumenta com a tensão negativa aplicada e com o número de varreduras. Também foram realizadas simulações para levantar as distribuições de tensão e de campo elétrico no sistema sonda-ar-silício ou sonda-ar-óxido-silício(substrato). Observou-se uma oxidação local assistida por um alto campo elétrico capaz de induzir difusão iônica local finita na extremidade da sonda. Foi simulado também o efeito das diferentes terminações de sonda do AFM, circular ou pontiaguda, no campo elétrico e na queda de tensão. Foram também realizadas oxidações com sondas recobertas com ouro em superfícies de Si precedidas de imersão simples em solução de ácido hidrofluorídrico seguido ou não do procedimento de limpeza SC1. Por fim, análises de absorção por infravermelho (FTIR) foram realizadas em superfícies de Si oxidadas por AFM para analisar a estrutura dos óxidos anódicos obtidos. A oxidação anódica utilizando sondas de nitreto de silício ocorre apenas após pré-limpeza terminada com SC1, sendo catalisada pelos altos campos elétricos (_ 106 V/cm), tendo como elementos reagentes, as espécies H2O adsorvidas e o óxido nativo hidrolisado na superfície após a etapa de limpeza SC1. / Local anodic oxidation of silicon using Atomic Force Microscopy (AFM) was investigated by applying a negative voltage between silicon nitride tip and Si surfaces. All samples were cleaned with an ammonium-based solution known in literature as standard cleaning 1 (SC1) or a dip in a diluted hydrofluoric acid solution followed by SC1 or, also, boiling in isopropyl alcohol. Localized squares patterns of oxide, 0.25 µm² in area, were formed by growing parallel lines with constant interlinear spacing and length and several scans in the same area. From AFM analysis with non-biased tip, it was obtained 3D and section profiles, which were used to obtain the oxide thickness as a function of the applied voltage, number of scans and interval of time after SC1 cleaning. It was noteworthy that thickness increases with the applied negative voltage and with the number of scans. Simulations were performed in order to model voltage and electric field distributions of the system tip-air-silicon or tip-air-oxide-silicon(substrate) indicating a local oxidation assisted by high electrical field and local ionic diffusion of species. It was simulated the effect of tip termination, circular or sharpen, on the electric field and voltage distributions. In addition, oxidations were performed using Au coated tips onto Si surfaces previously dipped in diluted hydrofluoric acid solution followed or not by SC1 cleaning process. Finally, infrared absorption analysis (FTIR) were performed in order to analise the structure of the obtained anodic oxides. The anodic oxidation using silicon nitride tips has occurred only after SC1 precleaning step, being catalized by high electric field (_ 106 V/cm), having as reagents, the adsorbed water species and hydrolized native oxide on the surface after the SC1 cleaning step.

[pt] Nesta dissertação de mestrado, nós desenvolvemos um processo de litografia baseado na técnica de microscopia de força atômica. O estudo do processo de litografia aqui utilizado inicia-se com a deposição e caracterização de filmes finos de sulfeto de arsênio amorfo (a-As2S3) em substratos de silício e a deposição de uma camada metálica de alumínio, utilizada como máscara, sobre a superfície do a-As2S3. O microscópio de força atômica é utilizado para escrever os padrões de forma controlada na camada metálica, e para tal, a influencia dos parâmetros de controle do microscópio na realização da litografia foi analisada. Para a transferência do padrão litografado realiza-se um posterior processo de fotossensibilização e dissolução química do a-As2S3 com uma solução de K2CO3. Após a dissolução, uma camada de ouro foi depositada por erosão catódica DC, seguido de uma nova dissolução, desta vez com NaOH resultando na transferência de nanoestruturas de Au para o substrato de silício. / [en] In this dissertation, we have developed a lithography process based on the atomic force microscopy of technique. The study of the lithography process starts with the deposition and characterization of amorphous arsenic sulfide thin films (a-As2S3) in silicon substrates and the deposition of a metallic aluminum layer, used as mask, on the surface of the a-As2S3. An atomic force microscope was used to write patterns in a controlled way on the metallic layer. Therefore, the influence of microscope feedback system on the accomplishment of the lithography was analyzed. In order to transfer the lithographed pattern to a silicon substrate, the a- As2S3 was exposed to a UV light source and was dissolved with a K2CO3 solution. Then, a thin gold layer was deposited by sputtering DC, and a new dissolution, now with NaOH was performed, leading to the deposition of Au nanostructures onto the silicon substrate.

Cette thèse porte sur la synthèse et la caractérisation photophysique d'une série de composés neutres luminescents de platine (II) contenant un ligand tridentate dianionique chromophore N-donneur et un ligand auxiliaire monodentate. Les composés montrent un changement notable des propriétés de photoluminescence selon l'auto-assemblage en raison de la formation d'interactions intermoléculaires non covalentes faibles telles que metal-metal et π-π. Nous avons démontré comment les complexes de Pt (II) peuvent être auto-assemblés d'une manière contrôlée et précise en jouant sur les facteurs cinétiques et thermodynamiques, ainsi que la morphologie des différents ensembles étudiés. Ces approches ont conduit à des matériaux avec des propriétés améliorées et uniques tels que le mécano-chromisme, ainsi que l'absorption et l'émission de la lumière polarisée. Les composés étudiés et leurs assemblages sont utiles non seulement pour le développement de nouveaux matériaux fonctionnels supramoléculaires en équilibre et hors- équilibre, mais aussi pour des applications en bio-imagerie. / This thesis focuses on the synthesis and the photophysical characterization of a series of luminescent neutral Pt(II) compounds containing a tridentate dianionic N-donor chromophoric ligand and a monodentate ancillary moiety. The compounds exhibited notable change of the photoluminescence properties upon self-assembly due to the establishment of weak non-covalent intermolecular interactions – metal-metal and π-π. We demonstrated how Pt(II) complexes can be self-assembled in a controlled and precise manner by playing with kinetic and thermodynamic factors and the morphology of the different assemblies investigated. Such approaches led to materials with enhanced and unique properties such as mechanochromism and polarized light absorption and emission. The investigated compounds and their assemblies were useful for the development of novel functional supramolecular materials in and out of the equilibrium as well as for bioimaging application.

<p>  </p> <p>The development of the semiconductor industry is encountering a giant leap recently as Moorse’s is extended to the next levels. Advanced nanomanufacturing technology is the major challenge in the way. Higher resolution down to a few nanometers as well as higher throughput is always the key. As the optical lithography determines the feature size, the photomask is still in need of a low-cost and high resolution maskless patterning tool. In another aspect, the growing information allows the generation and storage of data at ever faster rates, which has led to the era of big data reaching a heroic amount of 7 zettabytes of total data in 2020. Future growth requires the total shipment of data storage capacity to double roughly every two years or less. For the future generation of magnetic data storage, the bit patterned medium (BPM) in combination with the current heat assisted magnetic recording (HAMR) is expected to increase the areal storage capacity by another order of magnitude by physically isolating magnetic bits at the nanoscale. Electron beam lithography (EBL) as a universal maskless lithography technique shows great resolution but has a high tool cost and low process throughput. Scanning probe lithography (SPL) is another family of nanoscale patterning techniques with low tool cost but the practical throughput is still limited. For example, dip pen nanolithography utilizes an AFM probe as a writing pen in direct patterning, but the ink delivery is limited by the rate of ink’s capillary transport. Other SPLs such as thermal probes with capabilities of 3D fabrication and surface oxidation via chemical reactions are all facing similar limitations in throughput. One way of breaking this limitation is to use parallel writing with millions of probes which also faces uniformity problems. </p> <p>In this Ph.D. dissertation, we report our Surfing Scanning Probe lithography (SSPL) method which can boost the scanning speed of SPL by several orders of magnitudes at a low cost by using a hydro-aero-dynamic scanning scheme. We use a homemade patterning head to continuously scan over a partially-wet spinning substrate at a linear speed of meters per second. The head carries several metallic tips which emit electrons and induce electrochemical reactions inside a gap of 10 nm scale. We use a liquid phase precursor and deliver it using the near-field electrospinning method and microfluid structures during the fast patterning. The best linewidth demonstrated is about 15 nm in full-width half maximum (FWHM) which can be further improved using smaller scanning gaps and sharp probe tips. Besides direct writing with a liquid precursor, SSPL can work with gas precursors as well enabled by nano plasma. The rate of material deposition is much high than conventional SPL. The SSPL system is a low-cost nanopatterning technology to produce patterns at high throughput and high resolution.</p>

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.

In dieser Arbeit wird das epitaktische Wachstum von GaP/Si Heterostrukturen zur Herstellung von rauscharmen GaP/Si Nanodiodenarrays untersucht, wobei eine top-down Ätztechnik zur Herstellung der verwendeten Nanodiodenarrays genutzt wurde. Zur Untersuchung der gewachsenen Schichten wurden Röntgenstreuung (XRD), Rasterelektronenmikroskopie sowie die elektrische Charakterisierung mittels Strom-Spannungs und Kapazität-Spannungsmessungen verwendet. Zudem wurde die Grenzfläche zwischen epitaktischer Schicht und Substrat mittels Niederfrequenter Rauschspektroskopie (LFN) untersucht. Die GaP-Schichten wurden auf p-dotierten Si (100) Substraten mittels eines Riber-32P Gasquellen-Molekularstrahlepitaxiesystems gewachsen. Die Abhängigkeit der Oberflächenbeschaffenheit und Kristallqualität von denWachstumsbedingungen, wie der Wachstumstemperatur, wurden intensiv untersucht, um die Defektdichte zu minimieren. Dafür wurden nominal 500 nm dicke Heterostrukturschichten beiWachstumstemperaturen von 550 °C, 400 °C und 250 °C gewachsen, wobei 400 °C als die optimale Wachstumstemperatur bestimmt wurde. Trotzdem waren die erhaltenen Schichten aufgrund der hohen Versetzungsdichte von schlechter Qualität. Eine nur sehr geringe Qualitätsverbesserung konnte durch einen in situ durchgeführten thermischen Annealingschritt bei 500 °C für 10 Minuten erreicht werden. Daher wurde eine neue Annealingmethode vorgeschlagen, die in dieser Arbeit step-graded annealing (SGA) genannt wird. Bei dieser Methode wurde die Temperatur schrittweise von 400 °C auf 480 °C innerhalb von 90 Minuten erhöht. Dabei wurde die Oberfläche die gesamte Zeit mittels Reflexion hochenergetischer Elektronen (RHEED) untersucht. Die Oberflächenrekonstruktion, die während des Annealens mittels RHEED beobachtet wurde, zeigte schließlich eine große Verbesserung der Kristallqualität. Die Gitterparameter von GaP wurden mittels asymmetrischer XRD gemessen, wobei festgestellt wurde, dass sie exakt denen von Volumen-GaP entsprechen. Zudem wurde festgestellt, dass die GaP-Schicht automatisch n-dotiert ist und diodentypisches Gleichrichtungsverhalten aufweist. Interessante Informationen über Fallenzustände in den Heterostrukturfilmen konnten mittels LFN-Messungen gefunden werden. In einer nicht annealten Probe wurden beispielsweise zwei Fallenzustände im Bereich der Bandlücke festgestellt. In den mittels der SGA-Methode annealten Proben wurde hingegen ein rauscharmes und fallenfreies System erhalten. Anschließend wurde Elektronenstrahllithografie (EBL) zum Erstellen von Nanomustern auf der Oberfläche genutzt, die zur Herstellung von Nanodrähten genutzt werden sollen. Zur Optimierung der Elektronenstrahllithografie wurden dabei GaPSubstrate aufgrund der im Vergleich zu den epitaktischen Schichten besseren und glatteren Oberflächenstruktur genutzt. Dabei konnten in einer Goldschicht 200 nm große Löcher in einem Gitter mit hoher Dichte auf GaP erstellt und in die GaPSchicht übertragen werden. Die metallunterstütztes chemisches Ätzen (MacEtch) genannte Technik wurde kürzlich vorgeschlagen und eignet sich für die Herstellung von Nanodrähten. Die Anwendung zur Herstellung von Nanodrähten aus GaP war herausfordernd aufgrund bisher begrenzter Anwendung für III-V Halbleiter. Zur Optimierung der MacEtch Technik wurde zunächst wieder GaP-Substrat verwendet, um den Einfluss von Kristalldefekten und der Oberflächenrauigkeit auf die Ergebnisse zu minimieren. Genutzt wurde ein Gemisch aus Lösungen von HF/KMnO4 mit verschiedenen Konzentrationen. Mit den so bestimmten Prozessbedingungen konnten erfolgreich GaP Nanodrähte aus GaP-Epilayern hergestellt werden. GaP/Si Heteroübergangsnanodioden wurden anschließend unter Nutzung von Au-Ge/Ni Kontakten zu GaP-Schicht und Al/Ni Kontakten zum rückseitigen Si hergestellt. Die Transporteigenschaften des Nanodiodenarrays bestätigen die Möglichkeit, diese Arrays als elektronische NiederLärmbauelemente einzusetzen. / An epitaxial growth of GaP/Si heterostructures for the fabrication of low-noise GaP/Si nanodiode array based on nanowires is reported. The grown films were characterized using X-ray diffraction, scanning-electron microscopy, atomic-force microscopy and electrical measurements. Besides that, the interface between the epilayer and the substrate was deeply studied using a low-frequency noise (LFN) spectroscopy. The GaP epilayers were grown on p-type Si (100)substrates using gas-source molecular-beam epitaxy system. The dependence of surface morphology and crystal quality on the growth conditions was intensively investigated for minimizing the defects. The heterostructure films were grown at an optimal growth temperature of 400 °C and a nominal thickness of 500 nm. In order to improve the crystalline quality of the heterostructures, a new thermal annealing method was proposed, and referred to as step-graded annealing (SGA). In this method, the temperature was increased gradually to the annealing temperature to reduce the strain relaxation in the epilayers. A highly improvement in the crystal quality was confirmed using the SGA method. In addition, the epilayers were found to be n-type autodoped, and exhibited diode rectification behavior. Furthermore, the trap levels in the band gap, which were revealed via LFN measurements, were found to be suppressed in the annealed films. Thereafter, gold-mesh nanopatterns on the GaP surfaces were fabricated using an electron-beam lithography, as a step for the fabrication of GaP nanowires. A metal-assisted chemical etching technique with a mixture of HF:KMnO4 was carried out to fabricate GaP nanowires. GaP/Si heterojunction nanodiodes were then fabricated using an Au-Ge/Ni contact on the top of the GaP nanowires as well as an Al/Ni contact on the backside of Si. Transport properties of the nanodiode array confirmed the possibility of using the array as a low-frequency electronic device.

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.