bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Temperature Measurement During Oxide Chemical Mechanical Planarization
Authors: Cornely Jesse , Rogers Chris , Manno Vincent , Philipossian Ara 
Published: June 2019

AbstractThis paper presents temperature and friction force data at the pad-slurry-wafer interface during real time CMP polishing with in situ pad conditioning. Experiments are performed on a 1:2 scale laboratory tabletop rotary polisher with variable pad speed and wafer down force control. Dual emission laser induced fluorescence (DELIF) techniques are used to optically measure the temperature directly beneath the wafer during polishing using a two camera imaging system. An infrared camera and a thermocouple are alternately used to measure bow wave temperatures. Optically transparent BK-7 glass wafers with either concave (wafer edges sloping toward the pad) or convex (wafer edges sloping away from the pad) curvature were used. When concave wafers are polished, the bow wave temperatures are 3°C to 5°C higher than the corresponding value for convex wafers. Similarly, slurry temperatures under the concave wafers are 5°C to 6°C higher than the value for convex wafers (±0.5°C). The friction force per unit area is typically 2 kPa to 3 kPa higher for concave wafers. Temperatures beneath the wafer are as high as 12°C above the ambient temperature for a concave wafer at a high applied wafer pressure (41.4 kPa) or linear velocity (0.93 m/sec). Bow wave temperatures reach as high as 9°C above ambient at a linear velocity of 0.93 m/sec. The lowest temperatures, within 1°C of ambient at the bow wave and 5°C above ambient under the wafer, were found with convex wafers at low applied wafer pressures (20.7 kPa). Linear velocity has little effect on the slurry temperature while polishing convex wafers. Increasing slurry abrasive concentration causes an increase in temperature, despite a decrease in friction force. A correlation, with an R-squared value greater than 0.96, exists between the bow wave temperature and the temperature beneath the wafer. This correlation holds at constant linear velocities across wafer shapes, applied wafer pressures, and slurry concentrations.
A Novel CMP Process on Fixed Abrasive Pads for the Manufacturing of Highly Planar Thick Film SOI Substrates
Authors: Kulawski Martin , Henttinen Kimmo , Suni Ilkka , Weimar Frauke , Mäkinen Jari 
Published: June 2019

AbstractA new approach using Fixed Abrasive (FA) pads has been undertaken to overcome the problem of non-uniform thick film Silicon-on-Insulator (SOI) wafers after CMP polishing. The theoretical models indicating the advantages of the 2-body system of the fixed abrasive configuration vs. the conventional 3-body system of slurry based polishing have been convincingly demonstrated in practise upon experiments in a wide range of parameters. As a result it is possible to maintain or improve the flatness of wafers after back grinding, while simultaneously removing the sub-surface damage. A surface quality of prime wafers can be reached on the device layer. Capacitive thickness measurement scans and atomic force microscopy (AFM) monitoring confirm the results. A detailed comparison with conventional processing has been carried out to clarify the advantages on bulk silicon wafers. Decoration etching is used to analyse the wafer surface quality in terms of oxide induced stacking faults (OISF). As a result an alternative processing method is proposed for manufacturing thick film SOI substrates with improved uniformity.
Transient Electrochemical Measurements During Copper Chemical Mechanical Polishing
Authors: Lee Seung-Mahn , Choi Wonseop , Craciun Valentin , Singh Rajiv K. 
Published: June 2019

AbstractChronoamperometry was used to investigate the reaction/passivation kinetics and thickness of the chemically modified surface layer on the copper during chemical mechanical polishing (CMP). The result showed that the reaction/passivation kinetics and the thickness of the chemically modified surface layer are strongly dependent on the chemistry of CMP slurry in the chemical aspect of CMP and play critical keys in the selection of the chemistry and its concentration. BTA and H2O2 enhanced the passivation kinetics, resulting in thinner layer on the copper surface. In addition, the reaction kinetics increased as pH decreased.
The Effects of Particle Adhesion in Chemical Mechanical Polishing
Authors: Lu Zhenyu , Babu S.V. , Matijević Egon 
Published: June 2019

AbstractThe properties of abrasive particles, and their interactions with surface films to be polished, play a key role in chemical mechanical polishing (CMP). This study applies the packed column technique for the investigation of the adhesion phenomena at the particle/film interface as a function of different slurry chemistries relevant to polishing processes. Well-defined dispersions, including uniform spherical silica and silica cores coated with nanosized ceria, as well as calcined alumina were used to represent slurry abrasives, and copper or glass beads to simulate wafers or discs. It was shown that the pH and slurry flow rate had significant effects on particle attachment and removal. The results of deposition of silica particles on copper beads in the presence of various concentrations of H2O2 and of detachment from copper beads of alumina particles, loaded at different pH values, had strong correlations to the polish rates of the metal.
The Development of a Direct-Polish Process for STI CMP
Authors: Martin Antonella , Spinolo Giulia , Morin Sonia , Bacchetta Maurizio , Frigerio Francesca , Bonner Benjamin A. , McKeever Peter , Tremolada Maurizio , Iyer Anand 
Published: June 2019

AbstractThe development of a direct polish process for STI CMP on 200mm wafers using highselectivity slurry (HSS) has been achieved for production of 0.13μm technology microelectronic devices. The new process has improved on-wafer performance compared to standard STI CMP processes. The step height range across the wafer was decreased by 84%, planarity Cpk values (silicon nitride thickness and step-height uniformity) were increased by >25%, leakage current statistics were superior, and the cost of ownership was lowered by 78%. Cross-sectional SEMs both after direct polish CMP and after removal of the silicon nitride show improved planarity.
Dispersion Number Studies in ChemicalMechanical Planarization
Authors: Philipossian Ara , Mitchell Erin 
Published: June 2019

AbstractThis study explores aspects of the fluid dynamics of CMP processes. The residence time distribution of slurry under the wafer is experimentally determined and used to calculate the Dispersion Number (Δ) of the fluid in the wafer-pad region based on a dispersion model for non-ideal reactors. Furthermore, lubrication theory is used to explain flow behaviors at various operating conditions. Results indicate that at low wafer pressure and high relative pad-wafer velocity, the slurry exhibits nearly ideal plug flow behavior. As pressure increases and velocity decreases, flow begins to deviate from ideality and the slurry becomes increasingly more mixed beneath the wafer. These phenomena are confirmed to be the result of variable slurry film thicknesses between the pad and the wafer, as measured by changes in the coefficient of friction (COF) in the pad-wafer interface.
Effect of Tool Kinematics, Brush Pressure and Cleaning Fluid pH on Coefficient of Friction and Tribology of post-CMP PVA Brush Scrubbing Processes
Authors: Philipossian Ara , Mustapha Lateef 
Published: June 2019

AbstractReal-time coefficient of friction (COF) analysis is used to determine the extent of normal and shear forces during post-CMP PVA brush scrubbing and identify the tribology of the process. Fluid pH and applied pressure have pronounced effects on process tribology and the magnitude of COF. In cases where brush rotation is the only kinematic attribute of the system, low pH results in ‘mixed lubrication’ where increasing brush velocity causes a dramatic reduction in COF in accordance with classical tribological arguments. At lower pressures the tribological mechanism shifts to ‘hydrodynamic lubrication’ with significantly lower values of COF. Regardless of pressure, increasing the pH to 7 and 10.7 causes the tribology to remain in ‘hydrodynamic lubrication’ and results in even lower values of COF. Trends are explained qualitatively by considering the effect of pH on the solubility and gellation characteristics of silica in the silica-water system. Stribeck curves fail to shed light on the tribology of the system when complex ranges of tool kinematics (i.e. wafer rotation and brush oscillation superimposed on brush rotation) are employed. The results are counter-intuitive since they indicate nearly an order of magnitude increase in COF with increasing brush velocity. Nevertheless, results demonstrate the utility of having complex ranges of motion in PVA brush scrubbing such that very low or very high values of COF can be realized by simply increasing the rotational velocity of the brush while maintaining a constant wafer rotation and brush oscillation.
Selectivity Studies On Tantalum Barrier Layer In Copper CMP
Authors: Vijayakumar Arun , Du Tianbao , Sundaram Kalpathy B. , Desai Vimal 
Published: June 2019

AbstractCopper metallization in sub-0.18 μm semiconductor devices is achieved by combining the dual damascence techniques followed by chemical mechanical planarization (CMP). Tantalum and its nitride have been identified as the diffusion barrier layer for copper metallization. However, the wide differences in properties between copper and tantalum layers result in selectivity problems during CMP process. The aim of this work is to obtain a better understanding on the slurry selectivity for copper and tantalum and to develop slurries with best selectivity performance. In this work, the effect of several chemical parameters (abrasive type, oxidizer type, concentration, pH etc.) was studied through static and dynamic tests using advanced electrochemical techniques and surface analysis techniques. The surface layers of the statically etched copper and tantalum discs were investigated using X-ray photoelectron spectroscopy (XPS) and surface planarity was studied using atomic force microscopy (AFM). Polishing rates results show that alumina-based slurry polished copper very well whereas tantalum removal rate was low. However, for the silica-based slurry the tantalum shows much higher removal rate than copper and better surface planarity was obtained.
Comparison of Glycine and Citric Acid as Complexing Agents in Copper Chemical-Mechanical Polishing Slurries
Authors: Gorantla Venkata , Babu S.V. 
Published: June 2019

AbstractTwo complexing agents, glycine and citric acid, in hydrogen peroxide based slurries for planarizing copper have been compared. Copper dissolution and polish rates and in situ electrochemical experimental results at various slurry pH values and hydroxyl radical concentrations at pH=8.4 are presented. It was observed that the pH of the slurry has a strong influence on copper dissolution and polish rates. While high copper removal rates were observed with citric acid-peroxide solutions at low pH values, glycineperoxide system yielded high Cu removal rates at alkaline pH values. Copper dissolution rates in both the systems at pH 4 and 8 were consistent with the electrochemical measurements. The concentration of hydroxyl radicals generated in citric acid-peroxide system was less than that of those generated in glycine peroxide system at pH=8.4 indicating low copper removal rates at alkaline conditions in the former system.
In-situ electrical and spectroscopical techniques for the study of degradation mechanisms and life time prediction of organic based electronic material systems
Authors: Manca Jean , Goris Ludwig , Kesters Els , Lutsen Laurence , Martens Tom , Haenen Ken , Nesladek Milos , Sanna Ornella , Vanderzande Dirk , D'Haen Jan , Schepper Luc De 
Published: June 2019

AbstractIn order to tailor the synthesis of new robust organic materials for electronic applications and to guarantee the required life time for the emerging commercial plastic electronic applications it is of key importance to understand the underlying degradation mechanisms. Since plastic electronics is a rather young technology introducing new material systems, its reliability is characterized by new failure and degradation mechanisms, a relatively high amount of early failures and multi-modal failure distributions. To understand the mechanism responsible for a given failure or degradation mode, it is essential to study it separately, through appropriate test structures and test techniques. Powerful techniques for this purpose are a.o. analytical techniques (SEM, TEM, SPM,…), in-situ electrical measurement techniques and spectroscopical techniques (in-situ FTIR, in-situ UV-Vis, PDS). The benefits of these in-situ techniques in the reliability study of organic based electronics will be illustrated in this contribution.
Low Temperature Poly-Si on Flexible Polymer Substrates for Active Matrix Displays and Other Applications
Authors: Young Nigel D. , Trainor Michael J. , Yoon Soo-Young , McCulloch David J. , Wilks Richard W. , Pearson Andrew , Godfrey Sandra , Green Peter W. , Roosendaal Sander , Hallworth Elizabeth 
Published: June 2019

AbstractA variety of polymer materials including polyimide (PI), polyarylate (PAR), polynorbonene (PNB) and polyethersulphone (PES) have been studied for use as substrates in the formation of active matrix displays based upon polycrystalline silicon (poly-Si) thin film transistors (TFTs). A process used to fabricate transflective mobile phone displays at 250°C on such substrates is described in detail. The NMOS TFTs show a mobility of 100cm2/Vs, and a threshold voltage of 3.9V; the PMOS devices have a mobility of 52cm2/Vs, and a threshold voltage of -6V. Issues relating to performance of these devices, yield of the arrays, and manufacturability are discussed.
Flexible monocrystalline Si films for thin film devices from transfer processes
Authors: Berge Christopher , Wagner Thomas A. , Brendle Willi , Craff-Castillo Cecilia , Schubert Markus B. , Werner Jürgen H. 
Published: June 2019

AbstractTransfer of monocrystalline silicon films to arbitrary foreign substrates is a promising way for the fabrication of high quality silicon films on foreign substrates, demonstrated by solar cell efficiencies on glass as high as 16.6 % in the past. Transfer technologies also enable the use of flexible substrates. This paper investigates the mechanical stability of the separation layer for two different morphologies. First measurements on the minimum bending radius of unsupported silicon films are presented that allow us to estimate minimum curvatures for flexible monocrystalline devices. Finally, we report the first flexible monocrystalline thin film silicon solar cell of 4 cm2 with an independently confirmed efficiency of 14.6 %.
Organic Electronics for Large Area Electronic Devices
Authors: Chason Marc 
Published: June 2019

AbstractWith market opportunities continuing to drive electronic products to smaller size, significant research efforts continue to shrink semiconductor devices in accordance with Moore's Law. However, a new set of market opportunities is emerging for which the significant driver is not semiconductor complexity, but rather lower product cost arising from the novel integration of technologies making use of organic and flexible substrates. These new technologies present opportunities for research into new materials and fabrication processes. These new research opportunities extend from embedding passive devices, microfluidics, and polymeric optical waveguides in printed wiring boards, to organic transistors. This paper will discuss these new technologies and present some of the market forces driving these efforts.
Amoled Tft Pixel Circuitry for Flexible Displays on Metal Foils
Authors: Troccoli Matias , Afentakis Themis , Hatalis Miltiadis K. , Voutsas Apostolos T. , Adachi Masahiro , Hartzell John W. 
Published: June 2019

AbstractActive matrix organic light emitting diode displays based on thin, flexible metal foil substrates offer a novel approach to fabricate light, flexible and rugged displays. Metal foils allows devices to be fabricated at higher process temperatures yielding better device characteristics than plastic substrates. Furthermore, the conductive nature of such substrates enables more efficient use of pixel area through the use of a global power electrode. We are implementing Active Matrix Organic Light Emitting Diode (AMOLED) displays on flexible stainless steel substrate using 2 TFT and 4 TFT pixel circuit topologies with two different layout realizations that exploit the conductive properties of the substrate.
Oled Matrix-Displays
Authors: Metzdorf Dirk , Becker Eike , Dobbertin Thomas , Hartmann Soeren , Heithecker Dirk , Johannes Hans-Hermann , Kammoun Anis , Krautwald Henning , Riedl Thomas , Schildknecht Christian , Schneider Daniel , Kowalsky Wolfgang 
Published: June 2019

AbstractThe field of organic light emitting diodes (OLEDs) has matured considerably within recent years and first products are commercially available. After a brief review of the improvement of individual OLEDs we will focus on research topics for the preparation of passive matrix (PMOLED), active matrix (AMOLED) and full color displays. To date, the properties of organic matrix displays basically meet consumer product requirements. Anyhow an industrial cheap fabrication technology for reliable displays is not established yet. To meet the industrial demands for device fabrication a new horizontal in-line vacuum system for a massproduction compatible device manufacturing was installed. For material saving large area coatings the system accommodates up to 7” × 13” substrates. Different PMOLED-Displays based on vacuum deposited organic compounds have been prepared by various fabrication techniques. We demonstrate a 2 inch organic display with 24 × 32 single pixels and 0.9 × 0.9 mm2 pitch whereby cathode texture was achieved using photoresist barriers featuring a distinct undercut. Due to the inherent limitations of multiplexing and in order to satisfy the need for large area, high resolution displays the basic concepts for an active matrix addressing scheme are dealt with. In this regard transparent and electrically inverted top-side emitting diodes (IOLEDs) will be demonstrated. The latter are advantageous for the incorporation of powerful nchannel thin film transistors in the AMOLED driver backplanes. An all-organic smart pixel device comprising a single Pentacene based organic field effect transistor (OFET) and a conventional OLED was successfully prepared. Furthermore a new flash-sublimation technique for the spatially selective deposition of small organic molecules will be presented. We prepared OLEDs comprising flash-deposited Tris-(-8-hydroxyquinoline) aluminium (Alq3) and Alq3 doped with DCM2 which demonstrate the suitability of this technique for preparation of fullcolor displays based on small organic molecules.
Degradation in a Methyl-phenyl Co-Polymeric Polysilane for LED Applications
Authors: Sharma Asha , Deepak  , Katiyar Monica , Kumar Satyendra , Chandrasekhar V. , Saxena A. K. , Ranjan A. , Tiwari R. K. 
Published: June 2019

AbstractThe optical degradation of polysilane copolymer has been studied in spin cast thin films and solutions using light source of 325 nm wavelength. The room temperature photoluminescence (PL) spectrum of these films show a sharp emission at 368 nm when excited with a source of 325 nm. However, the PL intensity deteriorates with time upon light exposure. Further the causes of this degradation have been examined by characterizing the material for its transmission behaviour and changes occurring in molecular weight as analysed by GPC data.
Evolution of Nanocrystalline Silicon Layers Deposited at 150°C for Thin Film Transistor Channels
Authors: Cheng I-Chun , Allen Steven , Wagner Sigurd 
Published: June 2019

AbstractThin film transistors of nanocrystalline silicon (nc-Si:H) are made in the staggered topgate, bottom-source/drain geometry. To achieve both high carrier mobility and low off current, the nc-Si:H channel material must be kept thin but comprise a contiguous 10-nm thick crystalline layer at its top. We study this electrically most interesting top layer of the nc-Si:H channel film by AFM and SEM. Introducing an nc-Si:H seed layer underneath the TFT promotes the structural evolution of the nc-Si:H channel layer and raises the electron field effect mobility up to 40 cm2V-1s-1.
Fabricaton Ofactive Devices and Logic Gates on Fibers
Authors: Choi YongWoo , Kymissis Ioannis , Wang Annie , Akinwande Akintunde I. 
Published: June 2019

AbstractTextiles are a suitable substrate for large area, flexible and wearable electronics because of their excellent flexibility, mechanical properties and low cost manufacturability. The ability to fabricate active devices on fiber is a key step for achieving large area and flexible electronic structures. We fabricated transistors and inverters with a-Si film and pentacene film on Kapton film and cut them into fibers. The a-Si TFT showed a threshold voltage of 8.5 V and on/off ratio of 103 at a drain voltage of 10 V. These are similar to the characteristics of a TFT fabricated on a glass substrate at the same time. The maximum gain of the inverter with an enhancement n-type load was 6.45 at a drain voltage of 10 V. The pentacene OTFT showed a threshold voltage of -8 V and on/off ratio of 103 at a drain voltage of -30 V. The inverter with a depletion p-type load showed a voltage inversion but the inversion occurred at the wrong voltage. The antifuse was successfully programmed with a voltage pulse and also a current pulse. The resistance decreased from 10 GΩ to 2 kΩ after the programming.
Optimization of 75°C amorphous silicon nitride for TFTs on plastics
Authors: McArthur Christian , Meitine Mark , Sazonov Andrei 
Published: June 2019

AbstractAmorphous silicon nitride (a-SiNx) is widely used as the gate dielectric and passivation layer in a-Si:H based electronics. For devices on plastic substrates deposited at low temperature, the a-SiNx quality seems to determine the device performance. This paper investigates the effects of hydrogen dilution, helium dilution, ammonia-silane gas flow ratio, and RF power on the properties of PECVD silicon nitrides deposited in large-area parallel-plate reactors at substrate temperatures of 75°C. The chemical composition and bonding of the SiNx:H films was studied using FTIR spectroscopy. The physical properties were investigated, and the density, growth rate, and compressive stress of the films were determined. The electrical properties such as leakage current, breakdown, stability, trap density, and dielectric constant of the films were characterized by I-V and C-V measurements of metal-insulator semiconductor (MIS) structures. Analysis of Variance (ANOVA) was performed on the results, and the deposition conditions for the optimal film properties were determined. The optimum film had SiNx:H stoichiometry of x=1.56 with hydrogen concentrations of 17 at.%, and exhibited compressive stress of -220 MPa. The film displayed good stability under electrical stress with ohmic leakage of Rleak ∼1016 Ωcm. Strong relationships between the film properties and deposition conditions were observed, and are discussed within the paper. A-Si:H bottom gate TFTs were fabricated using the optimized nitrides for gate dielectrics and passivation layers, and the influence of a-SiNx on TFT performance is discussed.