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Zur Wandlung einer mechanischen Spannung in ein elektrisches Signal finden häufig Piezowiderstände Anwendung. Um den Flächenbedarf zu reduzieren und die Kompatibilität zu CMOS-Prozessen zu erhöhen, ist es möglich, MOS-Transistoren als Wandlerelement einzusetzen. Die Wandlung einer mechanischen Spannung in ein elektrisches Signal erfolgt unter Ausnutzung des piezoresistiven Effekts. Im Fokus dieser Arbeit stehen die Simulation und Charakterisierung von MOS-Transistoren als Wandlerelement für mechanische Spannungen. Zur Erzeugung der mechanischen Spannung fanden dünne Siliziummembranen Anwendung. Um die Transistoren in den Gebieten der maximalen mechanischen Spannung zu platzieren, wurden die Membranen mit einer FEM-Software simuliert. Der Stresseinfluss auf das elektrische Verhalten der Transistoren ist mit einem angepassten BSIM3v3-Modell simuliert worden. Die Skalierbarkeit wurde durch Simulationen von Halbleitertechnologien unterschiedlicher minimaler Strukturweiten nachgewiesen. Mit Hilfe der Messungen wurde der Stresseinfluss auf die Transistorkennlinien und Transistorparameter untersucht.

A polymer-based uniaxial accelerometer with piezoelectric polyvinylidene fluoride copolymer (P(VDF-TrFE)) transducers and micro injection molded polypropylene (PP) structures has been designed, manufactured and characterized. The mass-loaded cantilever structure shows a quasi-static charge sensitivity of 0.69 pC/g and a resonance frequency of 735 Hz. Because of its efficient processing and its small dimensions the polymer-based sensor (polySENS) can be integrated into polymer-based compound structures in order to measure low-frequency vibrations. The focus of this contribution is on the design, processing as well as on the characterization of the polySENS accelerometer to determine the sensor properties of the accelerometer due to manufacturing particularities. Additionally, investigations regarding the applied materials and the manufacturing, in particular the mold filling have been done to qualify the novel technological approach.

Extended Hückel theory (EHT) is a well established method for the description of the electronic structure of molecules and solids. In this article, we present a set of extended Hückel parameters for carbon nanotubes (CNTs), obtained by fitting the ab initio band structure of the (6,0) CNT. The new parameters are highly transferable to different types of CNTs. To demonstrate the versatility of the approach, we perform self-consistent EHT-based electron transport calculations for finite length CNTs with metal electrodes.

On-chip nanoporous gold (NPG) fabrication has been successfully developed by Au-Sn alloys electrodeposition and dealloying process, to use its compressible body and nanostructured surface for micro electro mechanical systems (MEMS) applications. Anodically-bondable low temperature cofired ceramic (LTCC) substrates are proposed to provide electrical connective packaging by using novel nano-structured gold. The porous structure offers sponge-like functions which forms electrical contacts as well during anodic bonding. Nanoporous gold with porosity in nanoscale indicates a highly reactive surface which makes it possible to be a promising candidate for bonding process to reduce the bonding temperature. Low temperature bonding has been achieved by using nanoporous gold. These encouraging results imply good possibilities of nanoporous gold for MEMS packaging applications.

In this work, the thermoelectric (TE) properties of poly(3,4- ethylenedioxylthiophene):poly(styrene sulfonate) (PEDOT:PSS) thin films at room temperature are studied. Different methods have been applied for tuning the TE properties: 1st addition of polar solvent, dimethyl sulfoxide (DMSO), into the PEDOT:PSS solution; 2nd post-treatment of thin films with a mixture of DMSO and ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4). It is verified that DMSO post-treatment is more efficient than DMSO addition in improving the electrical conductivity with a trivial change in the Seebeck coefficient. The power factor is increased up to 30.1 W mK-2 for the film with DMSO post-treatment, while the optimized power factor by DMSO addition is 18.2 W mK-2. It is shown that both DMSO addition and post-treatment induce morphological changes: an interconnected network of elongated PEDOT grains is generated, leading to higher electrical conductivity. In contrast, for t hose films post-treated in the presence of EMIMBF4, an interconnected network of short and circular PEDOT grains with increased polaron density is created, resulting in the improvement in the Seebeck coefficient and a concomitant compromise in the electrical conductivity. An optimized power factor of 38.46 W mK -2 is achieved at 50 vol% of EMIMBF4, which is the highest reported so far for PEDOT:PSS thin films to our knowledge. Assuming a thermal conductivity of 0.17 W mK-1, the corresponding ZT is 0.068 at 300 K. These results demonstrate that post-treatment is a promising approach to enhance the TE properties of PEDOT:PSS thin films. Furthermore, ionic liquid, EMIMBF4, shows the potential for tuning the TE properties of PEDOT:PSS thin films via a more environmentally benign process.

Carbon nanotubes (CNTs) are a promising material for novel sensor and interconnect applications. In both cases, the device performance depends strongly on the electronic properties of the tubes. Methods for tuning the electronic structure and especially the band gap are highly desirable. A computational study of cobalt decorated CNTs, by means of density functional theory, reveals that very few cobalt atoms can have a significant impact on the electronic structure, turning semiconducting CNTs into the metallic state. This is further verified by quantum transport simulations. The influence of different amounts of cobalt is also investigated.

Non-covalent functionalization based on surfactants has become one of the most common methods for dispersing of single-walled carbon nanotubes (SWCNTs). Previously, efforts have mainly been focused on experimenting with different surfactant systems, varying their concentrations and solvents. However sonication plays a very important role during the surfactant-based dispersion process for SWCNTs. The sonication treatment enables the surfactant molecules to adsorb onto the surface of SWCNTs by overcoming the interactions induced by the hydrophobic, electrostatic and van der Waals forces. This work describes a systematic study of the influence of the sonication power and time on the dispersion of SWCNTs. UV-vis-NIR absorption spectra is used to analyze and to evaluate the dispersion of SWCNTs in an aqueous solution of 1 w/v% sodium deoxycholate (DOC) showing that the resonant and nonresonant background absorption strongly depends on the sonication conditions. Furthermore, the diameter and length of SWCNTs under different sonication parameters are investigated using atomic force microscopy (AFM).

To realize fast and efficient integrated circuits the interconnect system gains an increasing importance. In particular, this is the case for logic and processor circuits with up to 12 metallization layers. In order to optimize this technology and the according processes it is desirable to generate flexible test structures in small lot production. In opposition to standard optical lithography using masks, Electron Beam Direct Write (EBDW) lithography can rapidly deliver special test structures at low cost. Furthermore, critical dimensions of future technology nodes which are not yet manufacturable by standard optical lithography tools can be produced. In this paper we demonstrate the potential of the 50 kV variable shaped EBDW cluster for patterning of future back-end-of-line (BEOL) structures on full 200 mm wafers. The patterned wafers have been used to develop next generation copper damascene interconnect processes for critical dimensions down to 50 nm.

The inhibition of Cu oxidation by alloying C into the Ru/TaN barrier stack is investigated. By using in-situ XRD measurement, severe copper oxide formation was observed for the Cu/Ru/barrier system during annealing process in He atmosphere. This phenomenon is explained using thermodynamics from the viewpoint of Gibbs free energy of oxide formation. The Cu oxidation can be inhibited by alloying C into the Ru layer, and the more C content in the RuC layer, the more evident the inhibition effect. The RuC/TaN stack also shows better diffusion barrier properties than the Ru/TaN bi-layer. Atomic layer deposition of Cu(2)O on the RuC substrate was carried out and reduction of the Cu(2)O to Cu was observed. The mechanism of inhibition of Cu oxidation on C alloyed Ru was investigated by a first principles calculation based on the density functional theory.

The subject of this paper is the extension of the simulation tool T2 for the application to Reactive Physical Vapor Deposition. The implemented models are briefly described and applied to the deposition of TaNx barriers. The influence of the nitrogen flow and the substrate bias on the deposition rate, the thickness uniformity, and the film composition is discussed.

The thermal atomic layer deposition (ALD) of copper oxide films from the non-fluorinated yet liquid precursor bis(tri-n-butylphosphane)copper(I)acetylacetonate, [(nBu3P)2Cu(acac)], and wet O2 on Ta, TaN, Ru and SiO2 substrates at temperatures of < 160°C is reported. Typical temperature-independent growth was observed at least up to 125°C with a growth-per-cycle of ~ 0.1 Å for the metallic substrates and an ALD window extending down to 100°C for Ru. On SiO2 and TaN the ALD window was observed between 110 and 125°C, with saturated growth shown on TaN still at 135°C. Precursor self-decomposition in a chemical vapor deposition mode led to bi-modal growth on Ta, resulting in the parallel formation of continuous films and isolated clusters. This effect was not observed on TaN up to about 130°C and neither on Ru or SiO2 for any processing temperature. The degree of nitridation of the tantalum nitride underlayers considerably influenced the film growth. With excellent adhesion of the ALD films on all substrates studied, the results are a promising basis for Cu seed layer ALD applicable to electrochemical Cu metallization in interconnects of ultralarge-scale integrated circuits. © 2009 The Electrochemical Society. All rights reserved. Es wird die thermische Atomlagenabscheidung (ALD) von Kupferoxidschichten, ausgehend von der unfluorierten, flüssigen Vorstufenverbindung Bis(tri-n-butylphosphan)kupfer(I)acetylacetonat, [(nBu3P)2Cu(acac)], sowie feuchtem Sauerstoff, auf Ta-, TaN-, Ru- und SiO2-Substraten bei Temperaturen < 160°C berichtet. Typisches temperaturunabhängiges Wachstum wurde zumindest bis 125°C beobachtet. Damit verbunden wurde für die metallischen Substrate ein Zyklenwachstum von ca. 0.1 Å erzielt sowie ein ALD-Fenster, das für Ru bis zu einer Temperatur von 100°C reicht. Auf SiO2 und TaN wurde das ALD-Fenster zwischen 110 und 125°C beobachtet, wobei auch bei 135°C noch gesättigtes Wachstum auf TaN gezeigt werden konnte. Die selbständige Zersetzung des Precursors ähnlich der chemischen Gasphasenabscheidung führte zu einem bimodalen Schichtwachstum auf Ta, wodurch gleichzeitig geschlossene Schichten und voneinander isolierte Cluster gebildet wurden. Dieser Effekt wurde auf TaN bis zu einer Temperatur von 130°C nicht beobachtet. Ebensowenig trat er im untersuchten Temperaturbereich auf Ru oder SiO2 auf. Der Nitrierungsgrad der TaN-Schichten beeinflusste hierbei das Schichtwachstum stark. Mit einer sehr guten Haftung der ALD-Schichten auf allen untersuchten Substratmaterialien erscheinen die Ergebnisse vielversprechend für die ALD von Kupferstartschichten, die für die elektrochemische Kupfermetallisierung in Leitbahnsystemen ultrahochintegrierter Schaltkreise anwendbar sind.

Copper(I) carboxylates of type [(nBu3P)mCuO2CR] (m = 1: 3a, R = Me; 3b, R = CF3; 3c, R = Ph; 3d, R = CH=CHPh. m = 2: 4a, R = Me; 4b, R = CF3; 4c, R = Ph; 4d, R = CH=CHPh. m = 3: 8a, R = Me; 8b, R = CF3; 8c, R = CH2Ph; 8d, R = (CH2OCH2)3H; 8e, R = cC4H7O) are accessible by following synthesis methodologies: the reaction of [CuO2CR] (1a, R = Me; 1b, R = CF3; 1c, R = Ph; 1d, R = CH=CHPh) with m equivalents of nBu3P (2) (m = 1, 2, 3), or treatment of [(nBu3P)mCuCl] (5a, m = 1; 5b, m = 2) with [KO2CCF3] (6). A more straightforward synthesis method for 8a - 8e is the electrolysis of copper in presence of HO2CR (7a, R = Me; 7b, R = CF3; 7c, R = CH2Ph; 7d, R = (CH2OCH2)3H; 7e, R = cC4H7O) and 2, respectively. This method allows to prepare the appropriate copper(I) carboxylate complexes in virtually quantitative yield, analytically pure form, and on an industrial scale. IR spectroscopic studies reveal that the carboxylic units in 4, 5, and 8 bind in a unidentate, chelating or ?-bridging fashion to copper(I) depending on m and R. The thermal properties of 4, 6, and 8 were determined by TG and DSC studies. Based on TG-MS experiments a conceivable mechanism for the thermally induced decomposition of these species is presented. Hot-wall Chemical Vapor Deposition experiments (CVD) with precursor 4b showed that copper could be deposited at 480 °C onto a TiN-coated oxidized silicon substrate. The copper films were characterized by SEM and EDX studies. Pure layers were obtained with copper particles of size 200 - 780 nm.

One well established technology for the fabrication of 3D devices in microelectronics and micro system technology is wafer bonding. After an overview about the existing bonding techniques the presentation will address aspects like bonding with plasma pretreatment to reduce the bond temperature below 200°C, use of nanostructures for bonding, metal to metal bonding and integration of new materials to form special SOI substrates.

Die Systemintegration und das miniaturisierte Packaging bestimmen in hohem Maße den Markterfolg elektronischer Produkte. Vielversprechende Perspektiven, um vom Nano- und Mikrosystem zum intelligenten Produkt zu gelangen, bietet das Konzept der "Smart Systems Integration".

Die Entwicklung von Mikrosystemen hat in Industrie und Forschung bereits erstaunliche Fortschritte gemacht. Dennoch ist nur einem kleinen Teil dieser Systeme der Markterfolg gelungen. Neben funktionellen Defiziten hemmen vor allem hohe Kosten für die Aufbau- und Verbindungstechnik die erfolgreiche Kommerzialisierung von Mikrosystemen. Ein synergetischer Entwicklungsprozess von der Entwurfsphase bis hin zum anwendungsspezifisch optimalen AVT-Konzept erweist sich hierbei als zentraler Erfolgsfaktor.

Mit beweglichen Sensorelementen aus Silizium lassen sich kleinste Neigungswinkel genau detektieren. Die dazu nötigen Mikrostrukturen werden mithilfe moderner Ätzprozesse kostengünstig hergestellt. Dank herausragender technischer Leistungsparameter sind derartige Sensoren auch für ein breites Anwendungsspektrum geeignet.