bluuebunny/crossref_metadata_2025 huggingface dataset:
A DLTS study of Pt/Al2O3/InxGa1
-
xAs Capacitors
Authors: Simoen Eddy R. , Brammertz Guy , Penaud Julien , Merckling Clement , Lin Dennis , Wang Wei-E , Meuris Marc
Published: September 2009

Deep Level Transient Spectroscopy (DLTS) has been applied to MOS capacitors (MOSCAPs) fabricated on n- and p-type GaAs and on n-type InxGa1-xAs epitaxial layers deposited by MBE on GaAs substrates. The gate dielectric consists of 10 nm ALD Al2O3. It is shown that the dominant deep levels in the case of GaAs MOSCAPs are two broad interface-state-related bands centered around midgap, which appear to be very similar to what has been found in the past for other gate dielectrics on GaAs. At the same time, it is reported that the interface-state peak shifts closer to the conduction band for the InxGa1-xAs layers, whereby the activation energy becomes smaller for higher x. However, it is demonstrated that in this case not only interface states contribute to the DLTS emission signal but also deep levels associated with threading dislocations (TDs) in the relaxed layers. This contribution grows progressively with the In content, i.e., with the amount of relaxation. From this, it is concluded that InxGa1-xAs/GaAs substrates are not favorable for inversion-type of MOS devices due to the increasing impact of the TDs on the device performance.
Two-dimensional Chemical Delineation of Junction Profile with High Spatial Resolution and Application in Failure Analysis in 65nm Technology Node
Authors: Liu Binghai , Hua Younan , Mo Zhiqiang , Adrian Ng
Published: September 2009

In this work, we reported a new FIB-assisted polishing technique and a new chemical junction-staining recipe for the chemical delineation of junction profile of a 65nm device. With the new polishing technique and recipe, two-dimensional junction profile was successfully delineated with a clear LDD (lightly doped drain) profile. The delineation of the LDD profile indicates the high chemical selectivity of the staining recipe. The as-developed new polishing technique and new junction-staining recipe were successfully applied to a real failure analysis case in which defects related to the inhomogeneous implantation process were successfully identified
3-D Modeling of Wafer Topography's Effect on Chemical Mechanical Polishing Process
Authors: Wu Lixiao , Yan Changfeng
Published: September 2009

In this paper, removal rate variation caused by wafer surface topography during CMP is studied based on 3-D solid-solid contact model. The height of the wafer topography is a function of two dimensions (). A new way to calculate the contact pressure between the wafer and the pad during CMP is proposed in the paper. It is found that if the topography of the wafer is represented as a linear combination of , then the contact pressure between the wafer and the pad can also be represented as a linear combination of the same signals with different amplitudes. A broad class of signals can be represented as a linear combination of . So the contact pressure can be obtained easily if the magnitude spectra and phase spectra of the system are known. This new method will be very helpful to establish the model of CMP and specify the polishing parameters during CMP. It can also provide help for getting contact pressure when a rigid surface with complicated topography contact with flat flexible base completely.
Drain Leakage Current Evaluation in the Diamond SOI nMOSFET at High Temperatures
Authors: Bellodi Marcello , Gimenez Salvador Pinillos
Published: September 2009

This paper presents a drain leakage current ILeak comparative study between conventional and the novel SOI MOSFET structure, known as Diamond transistor, operating from room temperature up to 300oC, regarding the same dimensions, aspect ratio, area and bias conditions, by using 3-D numerical simulations. It is shown that Diamond SOI nMOSFET presents larger drain leakage current (composed mainly by electrons) than conventional counterpart, due to its higher longitudinal electric field, which it depends on the hexagonal geometric shape of the gate-source/drain interfaces geometrics shapes. As far as "alfa" is close to 180o, the Diamond ILeak is practically the same as conventional SOI MOSFET.
The Characterization of Bottom-gate Thin Film Transistors adapted Nanocrystalline Silicon as Active Layer by Catalytic CVD at Low Temperature
Authors: Lee Youn-Jin , Lee Kyoung-Min , Hwang Jae-Dam , No Kil-Sun , Yoon Kap Soo , Yang Sung Hoon , Won Sunghwan , Sok Junghyun , Park Kyoungwan , Hong Wan-Shick
Published: September 2009

The nanocrystalline silicon bottom-gate thin film transistor (nc-si TFT) should improve on formed amorphous incubation layers at the onset of deposition because these layers deteriorate the performance of the transistor. We attempted modulation of hydrogen dilution ratio to achieve both the minimal incubation layer and high deposition rate. The incubation layer thickness was estimated by transmission electron microscopy (TEM) and crystallization fraction was measured by Raman spectroscopy.
The Technique to Characterize Irreversible Domain Motion in Ferroelectric Thin Films in a Large Time Scale
Authors: Jiang Anquan
Published: September 2009

Ferroelectric thin films after the field keep a large remanent polarization, i.e., the domain motion is irreversible. Obviously, the accessing speed of the ferroelectric memories depends on the domain switching time traditionally estimated from the position of a peaked current transient with time varying with the applied voltage. However, the circuit parasitics affects the shape of switching current transient and thus the accuracy of estimated domain switching speed. After simulation of the current transient with various circuit RC time constants and input pulse rising times, and a correct method is suggested, and the intrinsic field E dependence of domain switching speed ν at temperature T =77.6- 320 K is extracted. The dependence obeys the Merz's law ν∝exp(- α/E) with the activation field α∝1/T according to the domain nucleation model, suggestive of the common physics of domainswitching kinetics between the bulk ceramics and thin films.
Characterisation of High-k Containing Nanolayers by Reference-Free X-Ray Fluorescence Analysis with Synchrotron Radiation
Authors: Kolbe Michael , Beckhoff Burkhard , Krumrey Michael , Reading Michael A. , Van den Berg Jaap , Conard Thierry , De Gendt Stefan
Published: September 2009

Using reference-free X-ray fluorescence analysis (XRF) in different geometries carried out in the laboratory of the Physikalisch-Technische Bundesanstalt at the electron storage ring BESSY II in Berlin various nanolayered systems have been investigated. As an example the investigation of Hf containing thin oxide layers is shown. For comparison reasons these samples have been also measured by X-ray reflectometry (XRR) in the PTB laboratory and by other partners within the ANNA project, which confirmed the thickness of the Hf containing top layers determined by XRF within their respective uncertainties. The XRF spectra were deconvolved employing the detector response functions to deduce the intensity of the corresponding Hf L3 fluorescence lines. The investigation of nanolayered systems especially in the lower energy range shows advantages, like different absorption conditions which allow for better dynamics and the suppression of the silicon fluorescence signal from the substrate, but needs more effort in determining the respective fundamental parameters.
Si Wafer Analysis of Light Elements by TXRF
Authors: Sasamori Sato , Meirer Florian , Zoeger Norbert , Streli Christina , Kregsamer Peter , Smolek Stephan , Mantler Claus , Wobrauschek Peter
Published: September 2009

The determination of light elements (Z<14) requires a set of precautions and experimental modifications in comparison to the analysis of higher Z elements. All measurements have to be performed in vacuum around 1mbar pressure as achieved from a membrane pump. A high resolution energy dispersive detector with ultra thin window and efficiency high enough from 200eV upward is required. The analysis is performed under x-ray total reflection conditions (TXRF) and mechanical components for translation and rotation have to be foreseen for the adjustment. The measurement set-up consisted of a modified vacuum chamber suitable to accommodate 6"- 8" wafers on a rotatable sample carrier and will be described. Droplets containing Mg and two types of elemental matrices consisting of a) medium Z elements (Ti-Zn) and b) light elements (Na, Mg, Al) were prepared on 6" Si wafers in the laboratory of Siltronic AG in Freiberg. For the low Z elements concentrations of 10ng, 100ng, and 1000ng were taken and for the medium Z elements a variable concentration range from 1ng to 100ng was chosen. It was assumed that the presence of medium Z elements causes a stronger absorption of the light elements' fluorescence, whereas light elements affect each other non-serious. The results with respect to the made assumptions and detection limits for the new set-up will be shown.
Assessing Various Analytical Techniques with Different Lateral Resolution by Investigating Spin-coated Inorganic Contamination on Si Wafer Surfaces
Authors: Beckhoff Burkhard , Nutsch Andreas , Altmann Roswitha , Borionetti Gabriella , Pello C. , Polignano Maria Luisa , Codegoni Davide , Grasso Salvatore , Cazzini Elena , Bersani Massimo , Gennaro Salvatore , Kolbe Michael , Mueller Matthias , Kregsamer Peter , Posch Florian
Published: September 2009

The European Integrated Activity of Excellence and Networking for Nano- and Micro-Electronics Analysis (ANNA), www.ANNA-i3.net, addresses the development and assessment of new methodologies and metrologies for the detection of low concentration inorganic contaminants on and in silicon as well as for novel materials. The comparison of various analytical techniques available to the participating partners is important for assessment of both instrumentation and quantification reliability.
Comparability of TXRF Systems at Different Laboratories
Authors: Nutsch Andreas , Beckhoff Burkhard , Altmann Roswitha , Polignano Maria Luisa , Cazzini Elena , Codegoni Davide , Borionetti Gabriella , Kolbe Michael , Mueller Matthias , Mantler Claus , Streli Christina , Kregsamer Peter
Published: September 2009

The 'Analytical Network for Nanotech' is a European analytical infrastructure supporting the development of micro- and nano-technologies. High quality research requires comparability of results when analytical methodologies are supplied by different sources. This is a requirement of quality controlled industries, too. Inorganic contamination capabilities of the joint laboratory are Total Reflection X-Ray Fluorescence (TXRF) using Synchrotron Radiation (SR) or X-ray tubes, Vapor Phase Decomposition (VPD) and subsequent Graphite Furnace Atomic Absorption Spectroscopy (GF-AAS) or Inductively Coupled Plasma Mass Spectrometry (ICPMS), and Time of Flight Secondary Ion Mass Spectrometry (ToF SIMS). Discrepancies of results from different tools using TXRF for detection of metal contamination on silicon wafer surfaces were observed during different round robin using spin coated silicon wafers and deposited point like contamination. The results were validated using GF-AAS and ICPMS. The impact of the (reference) sample used for calibration on the evaluated measurement was confirmed. Furthermore, measurement geometries, substrate orientation and reliability of the angle of incidence are crucial for the comparability of the results of the TXRF systems.
Revealing Copper Contamination in Silicon after Low Temperature Treatments
Authors: Polignano Maria Luisa , Brivio Jacopo , Codegoni Davide , Grasso Salvatore , Altmann Roswitha , Nutsch Andreas , Pavia Giuseppe
Published: September 2009

In this paper we address the problem of revealing copper contamination induced in the device region by the final part of the process. A method to reveal the effects of copper contamination is identified based on the recovery of MOS capacitors from deep depletion. In the presence of copper contamination carrier generation is dominated by surface generation, which is not surprising because copper is known to be prone to surface segregation. Copper segregation at the wafer surface was also confirmed by TOF-SIMS measurements. The measurements of surface generation velocity are non-destructive and the required structures can be easily integrated in device wafers. However, a recovery of the copper-related surface generation velocity with the time spent after the thermal treatment was observed. For this reason, it is important that the measurements are carried out in a short time after the thermal treatment responsible for copper segregation at the wafer surface.
Preparation and Characterization of Nanocrystals using Ellipsometry and X-ray Diffraction
Authors: Petrik Peter , Milita Silvia , Pucker Georg , Nassiopoulou Androula G. , Van den Berg Jaap , Reading Michael A. , Fried Miklos , Lohner Tivadar , Theodoropoulou M , Gardelis Spyros , Barozzi Mario , Ghulinyan Mher , Lui Alberto , Vanzetti Lia , Picciotto Antonio
Published: September 2009

Nanocrystalline semiconductors embedded in dielectric matrices are currently under investigation for use in Si-photonics and in memory devices. The aim of a joint research activity in the FP6-ANNA*) project (http://www.i3-anna.org) is to develop and improve metrologies for the measurement of nanocrystal properties.
Effect of Nanodiamond Particles Incorporation in Hydroxyapatite Coatings
Authors: Pecheva Emilia , Pramatarova Lilyana , Toth Attila , Hikov Todor , Fingarova Dimitrinka , Stavrev Stavri , Iacob Erica , Vanzetti Lia
Published: September 2009

Nanodiamond particles (ND, 4-6 nm in size) were added to a simulated body fluid (SBF) and electrodeposition (ED) at biological conditions (370C, pH 7.4) was performed on Ti surfaces. The novelty in this work was the addition of the ND particles to the SBF solution used as the electrolyte for the ED of biomimetic HA. The results from Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), coupled with energy dispersive X-ray (EDX) spectroscopy revealed that the Ti surface was covered by white, dense and homogeneous HA layer. X-ray photoelectron spectra (XPS) confirmed the formation of calcium phosphate, calcium carbonate, calcium oxide and hydrated surface layer. The ND particles incorporation yielded increased Vickers hardness of the HA. No cracks were observed in the SEM images of the HA-ND layer, which testifies for its ductility and good residual stress.
Atomistic Modeling of Junction Formation: Tools for Physics Understanding and Process Optimization
Authors: Pelaz Lourdes , Aboy Maria , Marques Luis , Lopez Pedro , Santos Ivan
Published: September 2009

In this work we describe the basis of different atomistic simulation techniques and their application for process modeling. We analyze the influence of implant flux on the position of the amorphous/crystalline interface and the amount of residual damage. We also illustrate the challenges for doping narrow finFET devices. Atomistic modeling is used to give insight into the physical mechanisms and to provide clues for process optimization.
A Comparison Between Self-assembled Monolayers on Gold and Germanium Employing Grazing Incidence X-ray Absorption Spectrometry GIXRF-NEXAFS
Authors: Lommel Martin , Reinhardt Falk , Hoenicke Philipp , Kolbe Michael , Mueller Matthias , Beckhoff Burkhard , Kolbesen B.
Published: September 2009

In contrast to self-assembled monolayers on gold, there is a lack of suitable methods for the necessary pre-treatment of the substrate and the process of self-assembly on germanium. Organic molecules with thiol anchor groups are able to bond to hydrogen-terminated germanium surfaces (Ge-S bond) as well as to gold surfaces. We have prepared SAMs of alkylthiols with different head groups on germanium and gold (as reference). The surface has been characterised prior to and after SAM formation by Near-Edge X-Ray Absorption Fine-Structure (NEXAFS) spectrometry with synchrotron radiation. We succeeded in distinguishing the fluorine of the thiol head group from the fluorine residue of the preceding dip in HF on germanium on the basis of their peaks in NEXAFS spectra. Grazing Incidence X-Ray Fluorescence (GIXRF) provided information about the tilt angle of each monolayer.
Probing Patterned Wafer Structures by Means of Grazing Incidence X-ray Fluorescence Analysis
Authors: Osan Janos , Reinhardt Falk , Beckhoff Burkhard , Pap Andrea Edit , Torok Szabina
Published: September 2009

The reliable characterization of both nanoscaled structures and nanoparticles deposited on semiconductor surfaces using reference-free total-reflection X-ray fluorescence needs an accurate knowledge on the influence of surface structures on X-ray standing wave field (XSW). Artificial structures (pads) of known composition with identical lateral dimensions and different heights in the 10 to 100 nm range were prepared. Their influence on the angular dependence of the XSW has been investigated employing monochromatized synchrotron radiation in the laboratory of the Physikalisch-Technische Bundesanstalt at BESSY II.
Detection of Acidic Substances of H-X Type in Clean Room Air
Authors: Kames Jost , Leibold Andreas , Nutsch Andreas , Otto Michael
Published: September 2009

Cavity 'ringdown' spectroscopy is besides ion mobility spectroscopy another technique for the online detection of volatile compounds in air. Based on absorption spectroscopy, cavity 'ringdown' spectroscopy (CRDS) works by attuning light from a laser to a wavelength in the infrared spectrum at which a certain contaminant adsorption peak occurs. The concentration is calculated from the time it takes for the light to fade or 'ringdown' within an adsorption cell (cavity) which is filled with the gas to be analyzed. A test setup for generation of airflows contaminated with acids substances of H-X type was build and tested successfully. The setup was used to compare a cavity 'ringdown' spectroscopy with impinger sampling in combination ion chromatography. The developed methods can be used for the evaluation of HF-levels in the clean room air. CDRS can be used to monitor HF-levels under dynamic conditions of local sources continuously.
Synthesis of Microscale Lead Sulfide Disks by Patterned Self-Assembled Monolayer
Authors: Usui Takane , Dasgupta Neil P. , Jiang Xirong , Lee Wonyoung , Prinz Fritz B.
Published: September 2009

This work explores an approach to utilize nanosphere lithography (NSL) and atomic layer deposition (ALD) to fabricate an array of microscale disks of lead sulfide (PbS). In this approach, a mold to fabricate polymer stamps was produced by NSL. Using these stamps a patterned self-assembled monolayer (SAM) of octadecyltrichlorosilane (ODTS) was deposited using microcontact printing. The ODTS SAM functioned as a resist to block the growth of ALD PbS. The resulting PbS disks were characterized by scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) to confirm the morphology and stoichiometry. Regular arrays of microscale PbS disks were successfully fabricated. This is a potentially attractive methodology for fabrication of multi-layer devices.
Formation of CdxZn1-xS Films for Photovoltaic Buffer Layers by Atomic Layer Deposition
Authors: Bakke Jonathan R. , Bent Stacey F.
Published: September 2009

Cu(In,Ga)(S,Se)2, or CIGS, solar cell technology is one of the most promising and well-studied thin film photovoltaic systems. However, one of the main challenges for the adoption of CIGS is that the most common and successful n-type buffer layer is CdS which contains a known carcinogen, cadmium. To reduce the usage of Cd in the buffer layer, we have developed ALD processes to make graded buffer layers from CdS to Zn(O,S).
Quantum Dot Formation in Polymer Wires by Three-Molecule Molecular Layer Deposition (MLD) and Applications to Electro-Optic/Photovoltaic Devices
Authors: Yoshimura Tetsuzo , Oshima Akio , Kim Dong-Il , Morita Yoshinori
Published: September 2009

Using Molecular Layer Deposition (MLD), three kinds of molecules, that is, terephthalaldehyde (TPA), p-phenylenediamine (PPDA), and oxalic dihydrazide (ODH), were connected one-by-one with designated sequences to construct multiple quantum dots (MQDs) in conjugated polymer wires. With decreasing the quantum dot lengths, absorption peak energy of the quantum dots shifts to the higher energy side, indicating that the quantum confinement effect arises. As applications of the polymer wires with the MQDs, electro-optic materials for optical switches, and efficient and robust light absorption layers for waveguide type dye-sensitized photo-voltaic devices are described.
ALD of Vanadium Oxide
Authors: Musschoot Jan , Deduytsche Davy , Van Meirhaeghe Roland L. , Detavernier Christophe
Published: September 2009

Experiments on the atomic layer deposition (ALD) of vanadium oxide from vanadyl triisopropoxide are presented. Water and oxygen plasma based processes are compared to the thermal process which uses water as a reagent. The plasma enhanced processes enable a fast ALD of films in a wide temperature range (50-200{degree sign}C). Pure, crystalline V2O5 can be grown with oxygen plasma ALD at 150{degree sign}C. Water based ALD resulted in carbon-contaminated, amorphous vanadia. The plasma steps were monitored with optical emission spectroscopy.
Performance and Characterization of ALD Vanadium Oxide Catalytic Nanoliths
Authors: Stair Peter C. , Elam J. , Libera Joseph A. , Feng Hao , Pellin Michael J. , Kim Hack-Sung
Published: September 2009

Supported vanadium oxide species are active catalysts for the selective, oxidative conversion of hydrocarbons to useful chemicals. Both the catalytic vanadium oxide and the supporting oxide were synthesized by ALD on high surface powders and anodic aluminum oxide (AAO) nanoliths. The nanoliths were prepared by anodic oxidation of aluminum. 1 nm of ALD aluminum oxide acts as the support for vanadium oxide loaded by 1 to 18 ALD cycles of vanadyltri-isopropoxide/H2O2. Ultraviolet-visible absorption edges red shift as the vanadia loading increases. The edge energy of 1-cycle ALD VOx corresponds to isolated, tetrahedral VO4 in agreement with Raman spectroscopy. V-O-V bonds form with additional cycles producing a gradual increase in VOx domain size. Reaction rate coefficients for the oxidative dehydrogenation of cyclohexane show increased overall activity in the high loading catalysts but a higher specific activity in the low loading catalysts for cyclohexene formation.
Atomic Layer Deposition of Quantum Confined Nanostructures on Particles
Authors: King David M. , Liang Xinhua , Li Jianhua , Johnson Samantha , Weimer Alan W.
Published: September 2009

Atomic layer deposition (ALD) was used here to experimentally demonstrate the ability to deposit films that exhibit quantum confinement on spherical particle surfaces. Polycrystalline ZnO films ranging from ~1.5 to 15 nm in thickness were deposited via ALD using diethylzinc and hydrogen peroxide at 100{degree sign}C. Conformal, pinhole-free films were deposited on Si wafers and on nano-sized spherical SiO2 particles using an augmented central composite design strategy. A statistical design of experiments was performed to quantify the crystallite size of the primary peaks associated with polycrystalline ZnO, as well as the change in bandgap associated with the small crystal domains based on the number of ALD cycles and thermal annealing post-treatments. The shift in the optical bandgap of ZnO nanoshells was correlated to the domain size within the films at each point in the experimental matrix. The blue shift of 0.3 eV dissipated beyond crystallite sizes exceeding ~10nm, which was indicative of quantum confinement.
Physical Characterization of Zinc Oxide Thin Films Grown by ALD
Authors: Tapily Kandabara , Stegall David , Gu Diefeng , Baumgart Helmut , Namkoong Gon , Elmustafa Abdelmageed
Published: September 2009

We investigated the structural and mechanical properties of 400 nm and 40 nm thick ALD ZnO thin films. Diethyl zinc was used as the precursor for zinc and water vapor was used as the oxygen source. The samples were deposited at 150oC and at a pressure of 2.1x10-1 Torr. A growth rate of 2 Aå per cycles was calculated in the ALD process window. The Nanoindenter XP from MTS was used in conjunction with the continuous stiffness measurement (CSM) in depth control mode to analyze the elasto-mechanical properties of ALD ZnO thin films samples. For comparison we benchmarked the mechanical properties of single crystal bulk ZnO samples against our ALD ZnO thin films. We measured the modulus and hardness values of 125{plus minus}1.6GPa and 5.6{plus minus}0.09GPa respectively for our single crystal bulk ZnO reference sample.
In-situ Studies of Atomic Layer Deposition Studies on High-Mobility Channel Materials
Authors: Milojevic Marko , Sonnet Arif M. , Hinkle Christopher L. , Kim Hyun C. , Vogel Eric M. , Kim Jiyoung , Wallace Robert M.
Published: September 2009

The atomic layer deposition of high-k dielectrics on III-V materials envisioned for advanced CMOS is studied using in-situ mono-chromatic XPS. The impact of the control of the interfacial oxidation states is discussed, as well as the effect of the oxidation chemistry employed. We find that the control of the oxidation states is essential for useful device performance.
Atomic Layer Deposition of High-k Oxides on InAlN/GaN-based Materials
Authors: Abermann Stephan , Ostermaier Clemens , Pozzovivo Gianmauro , Kuzmik Jan , Bethge Ole , Henkel Christoph , Strasser Gottfried , Pogany Dionyz , Giesen Christoph , Heuken Michael , Alomari Mohammed , Kohn E. , Bertagnolli Emmerich
Published: September 2009

We demonstrate the applicability of atomic layer deposition of Al2O3 and ZrO2 on InAlN/GaN-materials by means of Metal Oxide Semiconductor High Electron Mobility Transistors (MOS-HEMTs). We investigate the impact of various surface pre-treatment methods, as well as the impact of in-situ pre-treatment by ALD on the electrical characteristics to evaluate insulation quality and thermal stability of the gate oxide stack, threshold voltage and interface traps. We show that by using the right surface pre-treatment as well as by using an adapted ALD pulsing scheme, one can obtain clearly improved MOS-HEMT performance concerning reduced gate leakage currents, suppressed current collapse effects, and increased drain currents
Effects of Surface Functionalization on Titanium Dioxide Atomic Layer Deposition on Ge Surfaces
Authors: Ardalan Pendar , Musgrave C. B. , Bent Stacey F.
Published: September 2009

Water contact angle measurements, ellipsometry, transmission infrared spectroscopy, x-ray photoelectron spectroscopy, Auger electron spectroscopy, and density functional theory were employed to study the atomic layer deposition (ALD) of titanium dioxide (TiO2) high-κ dielectric films on brominated, chlorinated, and 1-octadecanethiolate self-assembled monolayer (ODT SAM)-coated Ge(100) and Ge(111) substrates using titanium tetrachloride and water as ALD precursors. A strong dependence on temperature and type of passivation were observed for the TiO2 deposition rate, with deposition at lower temperature occurring to a significant extent only on the Cl-passivated Ge surface. It was found that bromination/thiolation is not compatible with area-selective ALD (ASALD) of TiO2 on Ge, since it would require growth at temperatures above 100 oC where ODT SAMs are not stable under the ALD conditions. On the other hand, the chlorination/thiolation route can be employed for selective deposition of TiO2 on Ge(100).
ALD Applications Beyond Outside IC Technology - Existing and Emerging Possibilities
Authors: Putkonen Matti I.
Published: September 2009

Today, the main industrial application of ALD is manufacturing semiconductor devices, both memory devices and microprocessors. Industrial ALD is, however, searching for new success stories from novel areas. Examples of new applications outside the semiconductor industry include photovoltaics, diffusion barriers, wear resistant materials and optical coatings, all aiming to improve the competitiveness of existing products and create new opportunities for ALD. In this paper we shortly review the existing and emerging application areas where ALD has been recently utilised. We will also show some new results concerning ALD on glass and metal substrates in order to improve the substrate's cracking and wear resistance, respectively. Different industrial ALD tool concepts and process requirements for high throughput production are also discussed.
Functionalization of Fine Particles Using Atomic and Molecular Layer Deposition
Authors: King David M. , Liang Xinhua , Weimer Alan W.
Published: September 2009

The functionalization of fine primary particles, including nanoparticles and nanotubes, is easily carried out using atomic or molecular layer deposition (ALD or MLD, respectively) techniques. Particle ALD/MLD can be used to deposit conformal and pinhole-free films of refractory oxides, non-oxides, metals, and hybrid polymer-based materials, amongst others. Fluidized bed reactors are well-suited for large scale operations and can be operated at reduced pressures while using inert gases necessary for standard self-limiting, flow-based ALD/MLD processes. The continuous-flow processing allows for process control using an in-line mass spectrometer downstream from the reactor chamber. Many insulator and semiconductor films, including Al2O3, ZnO, TiO2 and SiO2 have been successfully deposited on primary particle surfaces in fluidized bed reactors using a variety of precursor types. The applications of functionalized or passivated nanomaterials are innumerable, and the flexibility of this scalable process demonstrates its economic viability.
ALD Synthesis of Tube-in-Tube Nanostructures of Transition Metal Oxides by Template Replication
Authors: Gu Diefeng , Shrestha Pragya , Baumgart Helmut , Namkoong Gon , Abdel-Fattah Tarek M.
Published: September 2009

Multiple co-axial nanotube structures of various transition metal oxides were successfully synthesized by Atomic Layer Deposition (ALD) techniques utilizing nanoporous anodic aluminum oxide (AAO) as templates. In order to fabricate free-standing tube-in-tube nanostructures successive ALD nanotubes were grown on the interior walls of the AAO nanochannels. The co-axial nanotubes were alternated by sacrificial spacers of ALD Al2O3, to be chemically removed to release the nanotubes from the AAO template. This synthesis may be extended to fabricate n-times tube-in-tube nanostructures of different materials with applications in multi sensors, broad band detectors, nanocapacitors and photovoltaic cells by growing specific sequences of insulating, semiconducting and conducting ALD layers.
Highly Conformal ALD of ZrO2 at Higher Process Temperatures than the Conventinal TEMAZr-Based Process
Authors: Senzaki Yoshi , Okuyama Yoshi , Kim Gi , Kim H. Y. , Barelli Carl , Lindner Johannes , Karim Zia , Ramanathan Sasangan
Published: September 2009

An alternative Zr source to tetrakis(ethylmethylamino)zirconium (TEMAZr) was evaluated in this study to develop more thermally robust 300mm ZrO2 ALD process. It was observed that a transition from ALD to CVD takes place at approximately 340åC susceptor temperature. This temperature is significantly higher than that for the commonly used TEMAZr-based ALD process by approximately 40åC. Excellent step coverage of near 100% of ALD ZrO2 has been achieved in 40:1 aspect ratio structures using this new ZrO2 ALD process. ZrO2 ALD films of 5.5nm thickness demonstrated a low leakage current of 2x10-9A/cm2 at 1.2V.
Recent Development of ALD Precursors for Semiconductor Devices
Authors: Wada Senji , Sakurai Atsushi , Yamada Naoki , Watanabe Tsuyoshi , Uchiuzo Hiroyuki
Published: September 2009

Two novel precursors with a donor-functionalized ligand, tetrakis(1-dimethylamino-2-methyl-2-propoxy) zirconium (Zr(DMAMP)4) and tetrakis(1-dimethylamino-2-methyl-2-propoxy) titanium (Ti(DMAMP)4), are synthesized for the deposition of zirconium dioxide (ZrO2) and titanium dioxide (TiO2), respectively. Zr(DMAMP)4 and Ti(DMAMP)4 have nitrogen donor in their molecule in order to add two functions, thermal stability and reactivity with oxidants. For example, thermal stability of Zr(DMAMP)4 is more stabilized than those of our line-ups of Zr precursors. The role of nitrogen atom for the improvement of reactivity with oxidants is confirmed by thermogravimetric analysis (TG) under O3 atmosphere.
Novel "In-situ2" Approach to Modified ALD Processes for Nano-functional Metal Oxide Films
Authors: Tallarida Massimo , Karavaev Konstantin , Schmeisser Dieter
Published: September 2009

We describe our novel approach to the utilization of modified ALD routes for enhancing the functionality of metal-oxide thin films. The basic characteristic of our approach is the determination of the appropriate ALD parameters during the oxide growth. For monitoring the effects of the ALD parameters on the chemical-physical properties of the thin film, we implemented UHV-compatible ALD reactors for in-situ investigations using Synchrotron Radiation-XPS experiments. We show some example of how the in-situ optimization of ALD could be used to enhance the functionality of metal-oxide films, taking advantage of the extreme surface sensitivity of the experimental techniques used.
Patterning of ALD HfO2 Layers on Silicon
Authors: Andreu Robert , Sanchez Javier , Sanchez Ana , Zabala Miguel , Acero Maria Cruz , Rafi Joan Marc , Campabadal Francesca
Published: September 2009

A patterning technology for very thin layers of HfO2 layers grown by atomic layer deposition is proposed and evaluated in the case of patterning on silicon. This technology makes use of atomic layer deposited Al2O3 as a buffer layer, thus preventing silicon surface damage during HfO2 dry etching. The final surface roughness of silicon and of the patterned HfO2 layer as measured by AFM indicates that the proposed technology successfully leaves the silicon surface undamaged. The effects of photomasks overlapping have also been evaluated, which have lead to some design rules and buffer layer thickness requirements.
Optimizing the Release of ALD Grown ZnO Nanotubes from Anodic Aluminum Oxide Templates
Authors: Abdel-Fattah Tarek M. , Gu Diefeng , Baumgart Helmut , Namkoong Gon
Published: September 2009

Zinc oxide nanotubes were synthesized using atomic layered deposition (ALD) technique within anodic aluminum oxide (AAO) as a template and followed by removal of AAO using 0.4% NaOH solution for release of the nanotubes. Scanning electron microscopy (SEM) revealed preferential etching along grain boundaries of the resultant exposed ZnO nanotubes surface. Thermodynamic modeling diagrams were generated to optimize release of ZnO nanotubes from AAO.
Atomic Layer Deposition for All-Solid-State 3D-Integrated Batteries
Authors: Knoops Harm , Donders Merijn E. , Baggetto Loïc , Van de Sanden M. C. , Notten Peter , Kessels W. M.
Published: September 2009

All-solid-state 3D integrated batteries can reach the energy storage capacity required for future wireless devices by exploiting the third dimension. Conformal deposition techniques such as atomic layer deposition (ALD) are needed to deposit the battery materials. In this work, the current development of ALD processes for 3D integrated batteries is reviewed. We have developed both the TiN diffusion barrier and Pt cathode current collector processes. TiN showed good barrier properties in 3D, although a higher than expected charge density was observed, which could be attributed to a lower thickness and/or different material properties at the bottom of the 3D structures. The remote plasma ALD process for Pt showed fast growth initiation and good adhesion of the films. Furthermore, sufficient step coverage for the battery application was found. ALD is also potentially able to deposit the active battery layers, although the deposition of Li-containing materials is expected to be challenging.
ALD based Metal-insulator-metal (MIM) Nanocapacitors for Energy Storage
Authors: Banerjee Parag , Perez Israel , Henn-Lecordier Laurent , Lee Sang Bok , Rubloff Gary W.
Published: September 2009

In this paper, we demonstrate the feasibility of using metal-insulator-metal (MIM) capacitors for energy storage. Using an all-ALD approach we deposit TiN, Al2O3 and TiN as the three constitutive films for the MIM stack, inside high aspect ratio (upto 200:1), self assembled, nanoporous anodic aluminum oxide (AAO) templates. A 10µm deep porous template yields a planar capacitance density of ~100µF/cm2. The high capacitance values ensure the energy densities in these capacitors approach values close to electrochemical capacitors. Furthermore, the fast charge-discharge rates due to the electrostatic nature of these capacitors ensure that we achieve these energy densities without sacrificing high power densities. The MIM capacitors therefore have the potential to contribute to a broad range of electrical energy storage applications requiring high energy and power.
Detailed Correlation of Electrical and Breakdown Characteristics to the Structural Properties of ALD Grown HfO2- and ZrO2-based Capacitor Dielectrics
Authors: Schroeder Uwe , Weinreich Wenke , Erben Elke , Mueller Johannes , Wilde Lutz , Heitmann Johannes , Agaiby Rimoon , Zhou Dayu , Jegert Gunter , Kersch Alfred
Published: September 2009

Clear distinctions in the breakdown behavior of crystalline and amorphous dielectrics in MIM capacitors are correlated to different polarity asymmetries in the C-V and I-V characteristics of these symmetrical devices. Physical analysis of the complete capacitor stack reveals an oxidation of the TiN bottom electrode interface, leading to TiON formation and nitrogen diffusion into the dielectric. This can be traced back to the growth behavior of the dielectric on the TiN substrate. The atomic layer deposition caused interface formation is enhanced for crystalline films compared to amorphous, resulting in the asymmetry differences seen in electrical and breakdown characterization. In addition, asymmetrical charge trapping and a higher trap density are assumed for crystalline dielectric. These effects are detected both for doped HfO2 and ZrO2 layers.
Atomic Layer Deposition of Ru and RuO2 for MIMCAP Applications
Authors: Zhao Chao , Pawlak Malgorzata , Popovici Mihaela I. , Schaekers Marc , Sleeckx Erik , Vancoille Eric , Wouters Dirk , Tokei Zsolt , Kittl Jorge
Published: September 2009

Ruthenium (Ru) and Ruthenium-oxide (RuO2) are interesting electrodes for Metal-Insulator-Metal capacitor (MIMCAP) applications when combined with the high-k dielectric strontium titanate (SrTiO3). In this work, Atomic Layer Deposition (ALD) of Ru and RuO2 on TiN and SrTiO3 on 300 mm Si substrates is studied using a commercial thermal ALD reactor, and (Methylcyclopentadienyl)(Pyrrolyl)Ruthenium as a precursor and O2 as a co-reactant. It is found that a linear growth can be achieved for both Ru and RuO2 on a selected TiN after a short incubation. The deposition behavior and layer properties such as uniformity, adhesion and roughness depend strongly on substrate state. For the ALD of Ru on SrTiO3, surface treatment is needed for a controllable deposition: H2/He plasma treatment can activate the SrTiO3 surface and results in a linear growth of a metallic Ru layer.
Plasma-Assisted ALD of TiN/Al2O3 Stacks for MIMIM Trench Capacitor Applications
Authors: Hoogeland Dirk-Jan , Jinesh K.B. , Roozeboom F. , Besling W. F. A. , Lamy Y. , Van de Sanden M. C. , Kessels W. M.
Published: September 2009

In this paper we report on the overall plasma-assisted ALD processes of Al2O3 and TiN conducted in a single reactor chamber and at a single temperature (340 oC). The individual Al2O3 and TiN films in the stack were consecutively deposited in such a way that they were separated by purge intervals ranging from 15 to 300 s. Time-resolved mass spectrometry, TOF-SIMS depth profiles and C-V measurements of the deposited stacks show practically no evidence of precursor cross-contamination by the individual TiN and Al2O3 deposition steps. Based on these results and previous work on planar plasma-assisted ALD TiN/Al2O3/Si MOS capacitor structures, the way was paved to deposit a TiN/Al2O3/TiN/Al2O3 stack on high aspect ratio (~ 17) structures in silicon.
European SOFC R&D - Status and Trends
Authors: Steinberger-Wilckens Robert
Published: September 2009

The paper gives a ahort summary of European science and funding policy in the area of hydrogen and fuel cells and describes the technology status of SOFC technology in Europe. In high temperature fuel cell technolgy European companies and R&D groups have achieved a considerable level of success and established a firm European development basis.
The Status of SOFC Programs in USA 2009
Authors: Surdoval Wayne A.
Published: September 2009

The U.S. Department of Energy's (DOE) Office of Fossil Energy's (FE) National Energy Technology Laboratory (NETL), in partnership with private industry, educational institutions and national laboratories, is leading the research, development, and demonstration of high efficiency, fuel flexible solid oxide fuel cells (SOFCs) and coal-based SOFC power generation systems for stationary market large central power plants. The FE Fuel Cell Program has three parts under the Solid State Energy Conversion Alliance (SECA): cost reduction, coal-based systems, and research and development. The SECA cost reduction goal is to have SOFC stacks capable of being manufactured at $170 per kilowatt (2007 basis) by 2010. Concurrently, the scale-up, aggregation, and integration of the technology will progress in parallel leading to prototype validation of megawatt (MW)-class fuel flexible products by 2012 and 2015. The SECA coal-based systems goal is the development of large (greater than 100 MW) integrated gasification fuel cell (IGFC) power systems.
The Integrated Project SOFC600 Development of Low-temperature SOFC
Authors: Rietveld B. G. , Van Berkel Frans P. , Zhang-Steenwinkel Ye , Bouyer Etienne , Irvine John , Menon Mohan , Niewolak Leszek , Gross Sonja , Heel Andre , Holtappels Peter , Modena Stefano
Published: September 2009

The Integrated Project SOFC600 unites 21 partners jointly working on the research and development of SOFC stack components for operation at 600oC. The project is funded by the European Commission within the 6th Framework Programme. Low-temperature operation is considered essential for achieving commercial targets for lifetime and costs. This paper gives an overview of the activities in the project and of the main overall results achieved up to now.
A Review of Progress in the UK Supergen Fuel Cell Programme
Authors: Adjiman Claire , Atkinson Alan , Azad A. , Baker Richard , Brandon Nigel P. , Brett Dan , Clague Ralph , Carvalho Edwardo , Corre Gael , Choy Kwang-Leong , Irvine John , Marquis A. , Miller David , Offer Gregory , Pointon Kevin , Pyke Stephen , Selcuk Ahmet , Scott Keith , Shearing Paul
Published: September 2009

The Supergen fuel cell programme is the UK's flagship fuel cell research consortium, funded by the Research Councils. Established just under four years ago it brings together four academic partners (Imperial College, Newcastle University, Nottingham University and St Andrews University), three industry partners (Johnson Matthey, Rolls-Royce Fuel Cell systems and Ceres Power), and the UKs defence laboratory (DSTL), to work together to bring fundamental science to address key industry challenges in the fuel cell sector. This presentation will review progress made in tackling a number of key issues in solid oxide fuel cells, namely the constrained sintering of thick film electrolytes, electrolytes with higher conductivity at lower temperature, the relationship between fuel composition and anode behaviour - including work on sulphur poisoning and new anode materials, and new methods to characterize and model electrode performance.
Real-SOFC - A Joint European Effort to Improve SOFC Durability
Authors: Steinberger-Wilckens Robert , Bucheli Olivier , De Haart L.G.J. , Hagen Anke , Kiviaho Jari , Larsen Joergen G. , Pyke Stephen , Rietveld B. G. , Sfeir Josef , Tietz Frank , Zahid Mohsine
Published: September 2009

The Integrated Project Real-SOFC joined 26 partners from throughout Europe active in SOFC technology. The project was funded by the European Commission within the 6th Framework Programme and aimed at improving the durability of planar SOFC stacks to degradation rates of well below 1% per 1 000 hours of operation. This is an essential requirement in gaining access to the market for stationary applications. The underlying idea was to improve materials and materials processing on the basis of extensive test results identifying degradation mechanisms, and then to supply industrial components of enhanced quality for repeated testing analysis. This 'feedback loop' resulted in '2nd' and '3rd' Generations of SOFC components. This paper summarises the project approach, shows examples of the major results and of long-term durability testing.
Solid Oxide Fuel Cell Stack For Transportation and Stationary Applications
Authors: Mukerjee Subhasish , Haltiner Karl , Klotzbach Darasack , Vordonis Jim , Iyer Arun , Kerr Rick , Sprenkle Vincent , Kim Jin Yong , Meinhardt Kerry , Canfield Nathan , Darsell Jens , Kirby Brent , Oh Tak Keun , Maupin Gary , Voldrich Bill , Bonnett Jeff
Published: September 2009

Delphi is developing Solid Oxide Fuel Cell (SOFC) technology for applications in a variety of markets. This paper outlines the development of SOFC stacks for transportation and stationary applications. This paper outlines key achievements in stack development in moving forward towards meeting the goals for commercialization.
The Status of SOFC Development at Versa Power Systems
Authors: Borglum Brian P. , Tang Eric , Pastula Michael
Published: September 2009

Versa Power Systems (VPS) is a developer of solid oxide fuel cells (SOFCs) for clean power generation. VPS has been working with its development partner FuelCell Energy within the U.S. Department of Energy (DOE) Office of Fossil Energy's Solid State Energy Conversion Alliance (SECA) program to apply SOFC technology in large-scale, multi-megawatt power plant systems that utilize coal in a clean and efficient manner. As a result, new initiatives such as scale-up of the cell and stack are now being actively pursued for these applications.
Prototype SOFC CHP System (SOFIT) Development and Testing
Authors: Haga Tsuyoshi , Komiyama Norio , Nakatomi Hitoshi , Konishi Kinhei , Sutou Tetsuo , Kikuchi Tetsuo
Published: September 2009

Electric Power Development Co., Ltd. (JPOWER) started Tubular Type SOFC module development in collaboration with Mitsubishi Heavy Industries, Ltd. (MHI) in 1991. Since 2001 proof of concept of module structure, which was designed through the various trial and error, has been verified using the 5kW class cartridge and the 25kW class Sub module composed of 4 cartridges. The concept of module structure was verified with more than 1,400hrs operation using the 5kW class cartridge in 2003, followed by more than 500hrs operation of the 25kW class Sub module in 2006. Then the verification demonstration of the 150kW class atmospheric SOFC CHP system using accomplished module structure was planned. The prototype system was installed in 2006 and commissioning and operation test were started at the beginning of 2007. In this paper, the prototype atmospheric SOFC CHP system development and its operation test result are introduced.
Solid Oxide Fuel Cell Development at United Technologies Research Center
Authors: Sun Ellen , Yamanis Jean , Chen Lei , Frame Dustin , Holowczak John , Magdefrau Neal , Tulyani Sonia , Hawkes Justin , Haugstetter Christoph , Radcliff Thomas , Tew David
Published: September 2009

United Technologies Research Center is developing solid oxide fuel cell stack and system technologies. Our stack development is guided by comprehensive techno economic studies and system gap analyses. The effort is principally focused on stack design and component technologies for large stationary power generation applications, to address scale up, durability and cost challenges. Recent progress on interconnect alloys and coatings, cathode interfacial materials and glass seal materials will be reported. Our system development effort is focused on system integration and prototype validation. Highlights from recent 1-2 kW system testing will be presented.