bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism of Plasma-Less Gaseous Etching Process for Damaged Oxides from the Ion Implantation Process
Authors: Saito Suguru , Hagimoto Yoshiya , Iwamoto Hayato , Muraki Yusuke
Published: March 2009

Recently, plasma-less gaseous etching processes have attracted attention for their interesting etching properties. Previously, we reported on the etching properties of theses processes for various kinds of oxides and revealed that they reduce the etch rate of the chemical-vapor-deposited (CVD) oxides more than the conventional wet etching process does [1]. Our results also revealed that depressions called divots in the CVD oxide of the shallow trench isolation (STI) became smaller in size by substituting a plasma-less gaseous etching process for the conventional wet etching process. In semiconductor manufacturing, many processes are used to remove oxides damaged during ion implantation or reactive ion etching on the device surface. Therefore, it is very important to understand the etching properties of plasma-less gaseous etching processes for damaged oxides as well as those for other kinds of oxides. In this report, we evaluate the etching properties of one particular plasma-less gaseous etching process for oxide films damaged during the ion implantation process under various conditions and discuss the mechanism of interesting etching properties for the damaged oxides.
Current Advances in Anhydrous HF/Organic Solvent Processing of Semiconductor Surfaces
Authors: Roman P. , Torek K. , Shanmugasundaram K. , Mumbauer P. , Vestyk D. , Hammond P. , Ruzyllo Jerzy
Published: March 2009

The process in which anhydrous HF (AHF) is mixed with the vapor of an organic solvent for the purpose of etching of native SiO2 on Si surfaces is well established (e.g [1-4]). The process was also explored as part of a dry-wet wafer cleaning sequence [5]. More recently, the same process has been successfully expanded into MEMS technology for the purpose of stiction-free releasing of structures by isotropic etching of sacrificial SiO2 [6,7].
The current strong push in advanced Si digital IC technology toward extremely fragile 3D geometries engraved on Si wafer surfaces, in which case conventional etch methods may not work properly [8], as well as needs with regard to native oxide etching in emerging Si-based technologies such as solar cell manufacturing has brought about renewed interest in AHF technology.
Porous Low-k Wet Etch in HF-Based Solutions: Focus on Cleaning Process Window, "Pore-Sealing" and "k Recovery"
Authors: Broussous Lucile , Puyrenier W. , Rebiscoul D. , Rouessac V. , Ayral A.
Published: March 2009

In this study, the compatibility of "HF-Based" cleaning with porous low-k integration, and “pore-sealing” approach was investigated, and specific attention was paid to ultra low-k porosity evolution. We also tried to demonstrate if "k-recovery" could be achieved by thinning the modified surface layer in the pattern trench walls (plasma damaged layer), for 65nm and 45 nm design rules.
Impact of Dry Etch and Ash Conditions on Removability of Plasma Etch Residues in Al-Metallization. Approach to Improve PER Cleaning Efficiency by EHS-Friendly Aqueous Remover
Authors: Ferstl Berthold , Klipp Andreas , Essig Manfred , Heidenblut Maria
Published: March 2009

Driven by cost saving pressure and new regulations such as REACH, the imple¬mentation of cost efficient, EHS-friendly alternatives is in full swing. There is a clear trend in the plasma etch residue (PER) cleaning field to replace the currently used, expensive and harmful organic PER-removers by EHS-friendly aqueous alternatives. Striking advantages of fluorine free aqueous removal are reported1. The goals of present work -which was carried out in cooperation of BASF and Infineon-, was to examine the dependence of residue constitution on etch and strip conditions and to find a way to adapt also most critical cleaning challenges for EHS-friendly PER remover usage. For that reason a selected aluminum interconnect metal layer with difficult removable residues was chosen. XPS is well proved as an appropriate method for selective sidewall and top/bottom residue analysis2. Our analytical work was focused on defining fingerprints for the etch residues, concerning their elemental distribution, and tracking their changes during the different process steps and conditions.
Impact of CMP Polish and pCMP Cleaning on Adhesion of SiCN Capping Layer on PECVD-Derived Porous OSG and Copper
Authors: Gage Dave M. , Thiel A.D.W. , Dauskardt R.H. , Haas M.K. , Matz L.M. , O'Neill M.L. , Wieder T.M. , Banerjee G. , Rao M.B.
Published: March 2009

The development of robust integration processes for low-dielectric-constant materials is critical in order to meet the ITRS timeline. For 45 nm and beyond, the roadmap dictates use of an advanced dielectric material with a bulk dielectric constant below 2.5. These materials are produced through the introduction of nanometer-scale porosity into an OSG skeleton. The pore size, morphology, and interconnectivity is controlled by the choice of OSG precursor, pore former, and process conditions. During integration, liquids can be absorbed into the pore network (e.g. during the polishing and cleaning process steps, resulting in a degradation of the electrical and mechanical properties [1-3]. The objective of this paper is to evaluate the impact of the CMP and post-CMP cleaning process steps on cohesive fracture in a porous OSG dielectric and the adhesive fracture of SiCN cap with porous OSG and copper films.
Damage-Free Post-CMP Cleaning Solution for Low-k Fluorocarbon on Advanced Interconnects
Authors: Gu Xun , Nemoto Takenao , Teramoto Akinobu , Hasebe Rui , Ito Takashi , Ohmi Tadahiro
Published: March 2009

As technology node progressing, ultra low-k film has been implemented to reduce RC delay in LSI circuit. A fluorocarbon (CFx) film is proposed as foreground ultra low-k film because of non-porous structure [1]. Although CFx film is expected to be stable for its structure advantage, damage-less process is anticipated to avoid dielectric constants change in subsequence process steps [2]. CMP and post CMP process are concerned to bring damage on devices, so the effect of post CMP cleaning solutions on CFx structure and electric property is evaluated.
Applications of Electrostatic Spray Techniques to Surface Cleaning
Authors: Finster Ken , Small Robert , Belz Andrea , Mahoney John , Perel Julius , Gong Jian
Published: March 2009

Conventional cleaning technologies have been effective in removal of particles, metals, and organic films. However, two trends motivating the development of new techniques are 1) the desire to minimize the environmental impact of large volumes of cleaning solutions; and 2) the need to clean at the sub-45 nm level, consistent with decreasing feature sizes. We report here on the initial characterization of a system to apply electrospray techniques to variants of the SC-1 and SC-2 solutions, as well as to solvent mixtures. We describe the generation of submicron sized droplets (<1 m radius) of cleaning mixtures and demonstrate a preliminary methodology, using a combination of experimental data and phenomenological modeling approaches, to characterize the physics of the droplet-surface interaction
Analyzing the Collapse Force of Narrow Lines Measured by Lateral Force AFM Using an Analytical Mechanical Model
Authors: Wostyn Kurt , Kim Tae Gon , Mertens Paul W. , Park Jin Goo
Published: March 2009

When a physical cleaning technology, such as megasonic and high-velocity-liquid aerosol cleaning, is considered for the removal of particles or photo resist residues, damage addition is a major concern. After detection of defects in long gate stack lines by bright field inspection (KT2800), SEM imaging shows they extend over a length in the order of 1μm (Figure 1) [1].
Particle – Wafer Interactions in Semiaqueous Silicon Cleaning Systems
Authors: Hupka Lukasz , Nalaskowski Jakub , Sinha Nishant , Greeley Joseph N. , Clark Zak , Du Hao , Johnson William P. , Miller Jan D.
Published: March 2009

Interfacial interaction forces between particulate contaminants and semiconductor wafer surfaces play a key role in the understanding of post-CMP and post-lapping cleaning processes. In order to facilitate removal and prevent re-deposition of submicron particles on wafer surface, understanding, measurement, and manipulation of these forces is required.
The theory of interaction forces in liquids that includes DLVO forces (van der Waals, electrical double layer) and non-DLVO (solvation, hydration, hydrophobic, steric and bridging forces) is well established and is studied elsewhere.1-4 Short range interaction forces between silica surfaces in alcohols have been successfully measured before using AFM.5-7
Model of Vector Controlled Induction Drive
Authors: Rinkeviciene Roma , Petrovas Andrius
Published: March 2009

The paper presents the model of vector controlled induction motor. Induction motor model is carried out in reference frame, fixed on stator. Elaborated model of the drive is suitable for investigation dynamics because output signals appear as real currents, flux linkages and other variables. Vector control law model is implemented for variables in synchronous reference frame; therefore controller operates with transformed variables. Structure of designed model reflects the real variable speed drive. Model of vector controlled induction drive comprise model of induction motor, feedback signals and blocks as well as speed and flux reference blocks and controllers for producing motor supply signals. Feedback blocks are used for calculation stator current vector in the rotor flux linkage reference frame. For flux and speed control are designed lag controllers. Between advantages of that model is additional simulation of current channel law.
Novel Type of Hybrid 3-DOF Micromanipulator with Piezoelectric Actuators – Mechanical Construction and Simulations
Authors: Prusak Daniel , Uhl Tadeusz
Published: March 2009

The paper reports on the main assumptions and guidelines regarding construction of a novel type of parallel micro-robot with 3 degrees of freedom. Such micromanipulator is a hybrid construction, consisting of three arms connected together in parallel structure. The mechanical construction is a combination of rotational joints with bearings and flexible compliant joints so called: flexures. The whole construction measures several cubic centimeters and operates within c.a. 4 cubic centimeters workspace. In addition, the article relates to selected aspects of the control system, mathematical analysis of kinematics, basic simulations, specification of the range of movement of all actuators, and workspace of the moving platform. Modeling flexures using FE method will also be presented.
Flight Simulator as a Tool for Flight Control System Synthesis and Handling Qualities Research
Authors: Rogalski Tomasz , Tomczyk Andrzej , Kopecki Grzegorz
Published: March 2009

At the Department of Avionics and Control Systems problems of aeronautical control systems have been dealt with for years. Several different kinds of aeronautical control systems have been designed, prototyped and tested. These control systems are intended for general aviation aircraft and unmanned aircraft. During all research projects computer simulations and laboratory tests were made. However, since in some cases such tests were insufficient, in-flight tests were conducted leading to a series of reliable results. The in-flight tests were made with the use of M-20 Mewa aircraft (autopilot for a GA aircraft) and PZL-110 Koliber aircraft (control system for UAV and indirect flight control system for a GA aircraft). Nevertheless, in-flight testing is very expensive and problematic. To avoid some problems appearing during in-flight tests and their preparation, a simulator – which is normally used for professional pilot training – can be used. The Aviation Training Center of the Rzeszów University of Technology possesses the ALSIM AL-200 MCC flight simulator. We have started preparing this simulator for the research. It is possible to control the simulated aircraft with the use of an external control system. The solution proposed enables testing the aircraft control algorithms, indirect control laws (e.g. control laws modifying handling qualities), as well as testing and assessment of the students’ pilotage skills. Moreover, the solution makes it possible to conduct tests connected with aircraft control, crew management, crew cooperation and flight safety. The simulator allows us to test dangerous situations, which – because of safety reasons – is impossible during in-flight testing. This paper presents modifications to the simulator’s hardware and additional software, which enable the described research.
Web-Based Synthesis of Robot Structures for Micro and Nano Manipulations
Authors: Chakarov D. , Kostadinov K. , Gotseva D. , Tiankov T.
Published: March 2009

This paper describes how the web technologies are utilized for a robot system synthesis. A web application is created for automation of the synthesis of closed structures for micro- and nano-applications, utilizing the advantages tense piezo-actuators and closed robot kinematical structures. The algorithm, integrated into the developed web based application, offers a synthesis of robot kinematic chains without extensive knowledge in this domain.
The aim is to facilitate synthesis of such kind of kinematic chains from specialists who will generate optimal solutions for automation and robotisation of the requested micro- and nano-process.
LuGre Friction Model Estimation of a Precision Table and Sliding Mode Control Design
Authors: Huang Shiuh Jer , Chiu Chun Ming , Huang M.C.
Published: March 2009

Piezoelectric friction actuating mechanism is chosen to construct long traveling range sub-micro X-Y positioning table. LuGre friction model is employed to simulate the friction dynamics of this positioning mechanism. The optimization scheme of Matlab toolbox is adopted to search the optimal friction model parameters. However, this piezoelectric actuating system has obvious nonlinear and time-varying dead-zone offset control voltage due to the static friction and preload. The estimated LuGre dynamic model is still not accurate enough for model-based precision control design. Hence, the adaptive sliding mode control (SMC) with robust behavior is employed to design the nonlinear controller for this piezoelectric friction actuating mechanism. The Laypunov-like design strategy is adopted to achieve the system stability criterion. The dynamic experimental results of the proposed nonlinear controllers are compared with that of a model-based PID controller, too.
Permanent Magnet Chatter Absorber with Fuzzy Logic Control
Authors: Broel-Plater Bogdan , Domek Stefan , Parus Arkadiusz
Published: March 2009

The paper deals with semi-active chatter absorber based on an electrodynamic transducer built around high-energy permanent magnets. Also, a fuzzy logic control system for the absorber control system has been designed. The principal advantage of fuzzy control is the possibility to implement practical experience gained by machine operators in the control algorithm. Hence, the possibility of factoring such quantities, as vibrations experienced by selected points of the machine-tool, and sound emitted by working machine into the analyzed chatter absorber fuzzy control system has been studied in the paper. The control system has been tested by way of simulation with the use of the process and cutting force models.
The Effect of Controlled Frequency and Amplitude of Vibration on Friction
Authors: Abdo Jamil , Al-Yhmadi Amer
Published: March 2009

An in-house pin-on-disc apparatus is designed and constructed to perform the tests and the design of experiments technique is utilized to determine the effect of vibration, amplitude of vibration, surface roughness, and sliding speed and their cross influence on coefficient of friction for 304 stainless steel and Alloy 6061 Aluminum. The design is performed using response surface method (RSM). The coefficient of friction (CoF) is analyzed as a nonlinear function of the factors and predicted by a second-order polynomial equation. Results suggested that the presence of vibration affect the friction function CoF considerably for both metals. The friction function linearly decreases with the increases of vibration and amplitude of vibration, non-linearly decreases with the increases of sliding speed and linearly increases with the increases of the surface roughness until the middle range is reached and then there is non-linearly decrease thereafter. Similar trends of friction functions are observed for Alloy 6061 Aluminum with a reduction of almost 15% except for the case with amplitude of vibration where the variation showed more significant affect on the friction function when Alloy 6061 Aluminum disk is used.
A Computer Program Design for Optimization of a Cylindrical Traverse Grinding Operations
Authors: Marcinkevičius Andrejus Henrikas
Published: March 2009

Traverse cylindrical grinding productivity and accuracy depend on many factors of rough, fine and spark out grinding. Evaluation of all these factors at manual calculation of the process plan is impossible, for that reason the engineer technologist selects the cutting rates approximately, and they are far from optimal. We have deduced equations for calculation of optimal cutting rates for that purpose. Because of task complexity the computer program was designed for calculations which is described in this paper.
Optimal Synthesis Method for Invention of New Mechatronic Systems in Vibrotechnics
Authors: Lavendelis Egons , Viba Janis
Published: March 2009

The authors provide inverse method algorithm for invention mechatronic systems in vibrotechnics. The main difference of this method compared to a simple analysis method is that initial subsystem is solved before a synthesis of real system optimal control task for abstract. After the calculations optimal control law is found, which allows synthesizing series of structural schemes for real systems to close initial subsystem. It is also shown that near the optimal control excitation new structural schemes may be found within three kinds of strongly non-linear (impact) systems: systems with excitation as a time function; systems with excitation as a function of phase coordinates only; systems with mixed both excitations.
Fault Identifiability Problem – The Multi-Valued Diagnostic Model Approach
Authors: Borowczyk Henryk
Published: March 2009

The fault identifiability problem – determining necessary conditions of non-redundant set of symptoms that distinguish system’s faults – is considered. The diagnostic model is a multi-valued one. The information-theoretical approach enables determining redundant symptoms as well as indispensable symptoms - necessary elements of every diagnosis algorithm.
Energy Based Characterization of Fatigue Behaviour of Cyclically Unstable Materials
Authors: Macha Ewald , Slowik Jacek , Pawliczek Roland
Published: March 2009

The paper presents a definition of a new energy based parameter which allows to better describe fatigue proprieties of materials, especially cyclically unstable materials in comparison with the Lagoda-Macha parameter. The proposed parameter distinguishes positive and negative work of external force and depends on the sign of the stresses in paths of strain in materials. It is used in laboratory tests for control of a fatigue process on hydraulic stand. A close-loop control system has been equipped with computer program based on MATLAB/Simulink module.
Methodological Aspects of Evaluating Tribological Properties of Ball Bearings
Authors: Jałbrzykowski Marek , Nachimowicz Jerzy
Published: March 2009

The paper presents selected results of tribological tests on ball bearings. The elements for tests were obtained from their manufacturer. Two groups of ball bearings were evaluated: 134-781TNG-2RS and CBK 441TNG. Tribological tests were conducted with SMT-1 device in two-stage cycle. The first stage involved tests based on the authors’ own method. In the second stage the tests were conducted according to the manufacturer’s recommendations (methodology). The obtained results indicate varied tribological characteristics of the tested ball bearings, both in reference to the parameters of the external function and the applied test method.
Selective Transfer Phenomenon in Copper-Steel Tribological Systems
Authors: Kotnarowski Andrzej
Published: March 2009

The paper deals with possibility of selective transfer phenomenon generation in couples consisting of materials of railway traction trolley wire and of pantograph slider material. Some examinations are described concerning tribological characteristics evaluation of above couples.
The most characteristic condition of selective transfer phenomenon (known also under the name of “Garkunov effect”) is generation of specific protective metallic layer on friction surfaces of both frictionally cooperating elements that minimize wear and friction resistance. Obtained results led to the conclusion that the selective transfer phenomenon was generated in the model friction pairs examined in the frames of presented work. The magnitude of this phenomenon depended on minimal differences in quantities of additives and impurities in copper.
Development of Electromagnetic Ring Expansion Apparatus for High-Strain-Rate Test
Authors: Janiszewski Jacek , Pichola Wiesław
Published: March 2009

The structure of the experimental set-up for electromagnetic ring expansion and its electric properties are presented in the paper. While earlier expanding ring apparatuses were usually equipped with shaped-charge, thyratron or ignitron switches, we propose to use the impulse high-voltage thyritor as a switch to discharge capacitor bank. Furthermore, the preliminary results of the copper ring fragmentation properties are presented for different initial charge of capacitor bank (0,5 ÷ 2 kV). On the basis of our calculated and preliminary experimental data of the ring motion for expansion at 2 kV, we estimated the radial ring velocity, which was close to 250 m/s.
Swarm-Based Approach to Path Planning Using Honey-Bees Mating Algorithm and ART Neural Network
Authors: Ćurković Petar , Jerbić Bojan , Stipančić Tomislav
Published: March 2009

In this paper, an integration of Honey bees mating algorithm (HBMA) and adaptive resonance theory neural network (ART1) for efficient path planning of a mobile robot in a static environment is presented. The robot must find shortest route from given origin to the target position. Moreover, it should be able to memorize the environment and, if it faces known world, execute already learned trajectory found by HBMA solver, or solve the world and memorize the trajectory for the given environment. This is done using Adaptive Resonance Theory based neural network. This way simulated robot is able to navigate through environment and to continuously increase its knowledge.
Bone Ingrowth Processes on Porous Metalic Implants
Authors: Sidun Jarosław , Dąbrowski Jan Ryszard
Published: March 2009

The surface of an endosseous implant has fundamental importance in forming mechanical and chemical connection with osseous tissue. One of the methods of enlarging area is using technology of powder metallurgy. The paper presents research regarding osteointegration of porous materials for implants made for Co-Cr-Mo and titanium with Bioglass type-S2. The research was made on the castrated goats averaging one year of age, from this oneself herds. Bone growth process on surfaces of implants made with additional bioglass was significantly intense. The amount of osseous tissue and the number of connection points are significantly increased. On surfaces of titanium implants few areas of stochastic callus formation were observed. In that case areas of preferential bone integration have uneven surface due to technological process. A significant difference appears in osseous tissue growth morphology on implant surface. In porous implants bone grows around the pores of an implant. The obtained results showed that porosity influences callus growth intensity beneficially on the implant structure. Use of bioglass increases bone growth intensity on implant surface.
Effect of TiN Coating on Functional Properties of Implant Titanium Alloy
Authors: Grądzka-Dahlke Małgorzata , Bukrym Anna , Choińska Emilia
Published: March 2009

Surface engineering is considered a very prospective method of improving functional properties of implant alloys. Many publications reported the excellent influence of TiN coating on wear resistance as well as corrosion properties of titanium alloys. However, some authors pointed the danger of delamination of thin coating during exploitation. The aim of presented work was research of effect of TiN coating obtained by the RF-PCVD method on tribological and corrosion properties of Ti6Al4V alloy. Investigations performed by the simulator of hip joint friction as well as corrosion tests carried out at various temperatures showed adverse influence of TiN coating on wear and corrosion resistance. Analysis of presented date demonstrate that results strongly depend on test conditions.
The Problems of Exploitation Reliability Estimation of Dental Prosthetics Elements
Authors: Jałbrzykowski Marek , Kovalova Eva
Published: March 2009

The paper presents problems involving the assessment of durability and reliability of dental prosthetics elements. It describes the most common defects of such elements, with special focus on the prosthetic bridges. A lot of attention was paid to the complexity and extent of the problem and the structure of testers for investigating such elements. The analysis of literature is followed by the author’s own design of specialist research system for complex analysis of dental prosthetics elements.
The Behaviour Based Area Coverage of Unknown Environment by Autonomous Mobile Robot Using Modified "The Way of the Ox" Algorithm
Authors: Dąbkowski Mariusz , Grono Andrzej , Niklas Piotr , Redlarski Grzegorz
Published: March 2009

In paper the methodology of complete coverage of unknown area by autonomous mobile robot is described. The main principles of complete coverage task using sensory data only are given. The shape of coverage area is defined. The modified "the way of the ox" algorithm is proposed to realize this task and its following stages are described. Definitions of two quality indicators of realization of complete coverage task are given. The behaviour based control methodology imitated reactions of animals, realized the robot's movement, is presented. The general structure of reactive and proactive behaviours is showed. The example structures of defined reactive and proactive beheaviours, which allow to achive given task, are described. The example structure of complex behaviour implemented in Matlab-Simulink environment is presented. Graphical results of simulations of complete coverage task are presented. Values of quality indicators D and E are given and discussed.
Damping of Mechanical Vibrations Using Piezoelements, Including Influence of Connection Layer’s Properties on the Dynamic Characteristic
Authors: Buchacz Andrzej , Płaczek Marek
Published: March 2009

The paper presents analysis of flexural vibrating machatronic system. Considered system
is compounded of a cantilever bending beam and a strip-like piezoelectric transducer. The transducer is bonded with the beam surface by means of connection layer which has homogeneous properties in whole length. External RC circuit is adjoined to the transducer’s clamps. This mechatronic system is loaded with harmoniousness variable force. Beam’s vibrations affect piezoelectric transducer through the agency of connection layer which generates electric charge and produces additional stiffness. Dynamic equations of considered mechatronic system were determined on the basis of elementary beam and transducer’s section dynamic equilibrium. Transducer’s dynamic equation was assigned using transducer’s piezoelectric properties. Dynamic flexibility of considered mechatronic system was assigned on the basis of approximate Galerkin’s method. Solution of beam’s differential motion’s equation was defined as a product of time and displacement’s eigenfunctions which satisfy defined boundary conditions. Dynamic characteristic of considered mechatronic system, including pure shear of the connection layer was assigned on the end of the beam and illustrated on the chart at the same time taking into account beam and transducer’s geometrical and material parameters.
Sinterability of Silicon Nitride Powder Produced by the CRN Process
Authors: Atasoy Ahmet , Tümer M.
Published: March 2009

In the present work, laboratory experiments were carried out on the sintering of silicone nitride powder without any sintering additives. Silicone nitride powder was produced at own laboratory conditions by carbothermal reduction-nitriding of silica of which was presented elsewhere. It consists of mainly -Si3N4 (83%) and -Si3N4 (17%) phases with a small amount of minor constituents. Before compaction procedure, the powder was ball milled for 2 h and then 2 gr. of the sample was compacted uniaxially at a pressure of 25 MPa. The green compact was placed into furnace in a graphite crucible. The sintering process was carried out in a programmable muffle furnace at 1700 °C and held for 1 h. with a 20 °C/min. heating rate. The sintered compacts were analyzed using X-ray, SEM, SEM-EDS techniques. The results showed that the formation of liquid phase can accelerate the densification of the compact. The densification of the pure SIALON can be increased by adding of sintering aids that accelerates the formation of liquid phases in the sample. The densified sialons give better hardness and thermal properties of the sample. It was well demonstrated that for the densification of sialons large amount of liquid phase forming oxides are needed to add to initial composition. It is also suggested that there is linear relationships between densification and amount of liquid phase formed in the compact.
Modelling of Solid Part Using Multibody Techniques in Parametric CAD Systems
Authors: Łukaszewicz Andrzej
Published: March 2009

In this paper, the multibody approach to design in part environment in parametric CAD systems is described. Different kinds of multibody methods and tools which apply this approach are discussed. Some examples of solid part design performed in SolidWorks 2007 system are presented.
Order-Disorder Transitions and Thermodynamic Properties of M-Type Hexaferrites
Authors: Parida Suresh Chandra
Published: March 2009

Owing to the technological importance of M-type hexaferrites of general formula MFe12O19 (M = Ba, Sr and Pb) and their substituted analogues, a staggering number of research activities on their synthesis, magnetic properties and thermal properties are being pursued in recent years. However, many critical issues on the effect of aliovalent ion substitution either on the M-site or Fe-sites are still unexplored. This paper deals with a survey of crystallochemical and thermodynamic properties of this important class of ferrimagnetic oxides.
Recent Developments in Co-Base Alloys
Authors: Sahay S.K. , Goswami B.
Published: March 2009

Cobalt base alloys are being designed and developed to produce the best possible combinations of high temperature properties. Existence of martensite forms consisting of various intermetallic compounds has been described along with the variables associated with fcc-hcp transition at respective conditions of formation. Achievements of cobalt base alloys have been primarily due to various thermodynamic and kinetic parameters for most suitable combinations of alloying. The phase transformations in this review include the study of defect structure, martensite transformation, order-disorder kinetics, and recrystallization and grain growth mechanisms. The improvements in mechanical properties stem from the contribution of additional alloying elements to discontinuous precipitation, diffusion mechanism at grain boundaries and changes in compressive strength, yield strength, elongation and brittleness. L12-compound in cobalt base alloys possesses an important identity, which changes the characteristics of usable compositions.
Statistical Thermodynamics and Surface Phase Transitions of Interacting Particles Adsorbed on One-Dimensional Channels Arranged in a Triangular Cross-Sectional Structure
Authors: Pasinetti P.M. , Romá F. , Riccardo J.L. , Ramirez-Pastor A.J.
Published: March 2009

Monte Carlo simulations and finite-size scaling analysis have been carried out to study the critical behavior in a submonolayer lattice-gas, which mimics a nanoporous environment. In this model, one-dimensional chains of atoms were arranged in a triangular cross-sectional structure. Two kinds of lateral interaction energies have been considered: (1) wL, interaction energy between nearest-neighbor particles adsorbed along a single channel and (2) wT, interaction energy between particles adsorbed across nearest-neighbor channels. We focus on the case of repulsive transverse interactions (wT > 0), where a rich variety of structural orderings are observed in the adlayer, depending on the value of the parameters kBT/wT (kB being the Boltzmann constant) and wL /wT. For wL /wT = 0, successive planes are uncorrelated, the system is equivalent to the triangular lattice, and the well-known [ ] ordered phase is found at low temperatures and a coverage, , of 1/3 [2/3]. In the more general case (wL /wT  0), the competition between interactions along a single channel and the transverse coupling between sites in neighboring channels leads to a three-dimensional adsorbed layer. Consequently, the and structures “propagate” along the channels and new ordered phases appear in the adlayer. The influence of each ordered phase on adsorption isotherms, differential heat of adsorption and configurational entropy of the adlayer has been analyzed and discussed in the context of the lattice-gas theory. Finally, the Monte Carlo technique was combined with the recently reported free energy minimization criterion approach (FEMCA) [F. Romá et al.: Phys. Rev. B Vol. 68 (2003), art. no. 205407] to predict the critical temperatures of the surface-phase transformations occurring in the adsorbate. The excellent qualitative agreement between simulated data and FEMCA results allows us to interpret the physical meaning of the mechanisms underlying the observed transitions.
Simulation of Self Formation in Solar Cell Technology
Authors: Leonas Liudas , Janušonis Stepas
Published: March 2009

Relatively high cost of energy produced by solar cells prevents them from being used widely. One of the ways to address this problem is to create new, cost efficient solar cell production technologies. This presentation analyzes how, by applying self-formation principles it is possible to decrease number of photolithography processes used in high efficiency solar cell production, thus significantly reducing the cost of solar cell itself. All known planar technologies can be described based on self-formation principles; new microchip and integrated circuit technologies were created using self-formation as well. It is therefore natural to extend self-formation to solar cell technology. This presentation provides specific aspects of self-formation simulation as related to solar-cell technology. The object of the simulation is a cross-section of solar cell in two-dimensional Euclidean space and it.s evolution over time. Such kind of solar cell approximation simplifies the model, yet keeps all essential characteristics of the solar cell. The cross-section contains geometrical figures which approximate objects in the solar cell. Each figure is assigned with an integer parameter, approximating physical material. According to self-formation principles, evolution of each figure depends only on geometrical configuration of the figure itself, the parameter and interaction rules. Interaction rules define change of neighbouring points and approximate technological processes (etching, oxidation, coating etc). Combination of such processes enables construction of required solar cell configuration, with only minimum use of photolithography processes. Self-formation is simulated by two-dimensional 8-neighbour cellular automata based mechanism.
Self-Formation of the Artificial Planar Systems. What is It?
Authors: Janušonis Stepas
Published: March 2009

Self-formation concept as a generalization of the huge number of technologies in microelectronics was defined. Self-formation as irreversible evolution, causing self-increasing of an object complexity, is presented. Differential equation method allows description of evolution of any figures contour. Numerical model of self-formation in essence is a cellular automata of the second kind. Neither analytical nor numerical models did not involve causes of contour evolution. However causes of evolution are hidden in interactions of parameters which approximate an object and ambient materials. On the basis of above-mentioned factors, the right-dimensional topological space was created. It is the Cartesian product of the eight sets, including three Euclidean space axes, four parameter axes (defining parameters of the Euclidean points and interaction matrix) and time axis. Self-formation is a result of non-homogeneous mapping sequence in time. On the other hand non-homeomorpheous mapping indicates irreversibility of an evolution. Evolution is irreversible in time if only the object either contains the peculiar points or they arise under evolution. Therefore an interaction, defining the figure evolution out-side, does not return the object to initial state after its diversion inside and can implicate the complexity increasing. The new self-formation technologies for electron devices and integrated circuits manufacturing were carried out. Topological approach allows analysis and synthesis of real world structures, known in the areas of microelectronics, nanotechnology, photovoltaics and fuel cell technology, possibly in living world (genes, cells, organs, organism) as well. Problems remaining to be investigated are presented.
Technological Graph of Self-Forming Solar Cell
Authors: Janušonienė Vida , Leonienė E. , Leonas Liudas
Published: March 2009

Solar cell (SC) cost reduction remains the main problem in PV development. Selfformation technology implementation is one of the ways to decrease this cost.
It is known planar object.s evolution approximation by 8-dimensional topological space, containing object geometry, set of parameters, medium set and matrix of interaction. There we can have some different cases: external formation, self-formation, development and reproduction. However in case of self-formation, these attributes are not sufficient, because the different sequences of media can be created from the same set of medium. In external formation all structured and chaotic media are brought from outside and technological graph is created from recurrent parts. There we see an object interaction with different structured media, which structures are transferred to evolving object, and recurrent sequence of chaotic media (deposition, exposure, development, etching, diffusion and oxidizing). Initial technological object, interaction matrix and set of interactions are not sufficient to unambiguous technological process describing in self-formation case as well. Some technological graphs may be valid to one interaction matrix and result different
final object. Medium there are changed from outside but the initial object changes as the result of interaction with medium. In optimal case one structured medium (for initial object formation) and the sequence of chaotic media are necessary to manufacture the solar cell from the silicon wafer.
The approach of technological graph to solar cell technology is presented. Graphs of external formation and self-formation of solar cell are compared.
Behavior of Hydrogen in Al, Mg and MgAl Plasma Saturated Films
Authors: Milčius Darius , Pranevičius L.L. , Nomgaudytė Jurgita , Barnackas Irmantas
Published: March 2009

The behaviors of hydrogen in Al, Mg and MgAl thin films on stainless steel substrate were investigated in this work. The hydrogen ions extracted from plasma were used to load hydrogen into the film material. Glow discharge optical emission spectroscopy (GDOES) was applied to obtain the hydrogen depth profiles in Al films versus hydriding parameters. The MgH2, AlH3 and Mg(AlH4)2 hydrides were identified in plasma hydrided films using X-ray diffraction (XRD). It is shown that efficient supply transport of hydrogen from the surface into the bulk for Mg films takes place at temperature above 100 °C and ion irradiation intensity above 1 mAcm-2.
Self Formation of Porous Silicon Structure: Primary Microscopic Mechanism of Pore Separation
Authors: Kompan M.E. , Gorodetski A.E. , Tarasova I.L.
Published: March 2009

A microscopic mechanism of the self-formation of a dense pore system in the porous
silicon is proposed. According to it, the process of porous silicon self-formation is dictated by the laws of dynamics for a charge carriers system. The proposed mechanism is proved by the results of computer simulation. The values of inter-pore separation distance in p-type based porous material and anodization current threshold density are evaluated; the dependence of an inter-pore separation distance on the carriers concentration, close to n-1/2, is predicted.
The Role of Processes on the Surface in Organization of Long Range Mass-Transport in the Bulk
Authors: Pranevičius L.L. , Milčius Darius , Knizikevičius R. , Nomgaudytė Jurgita , Bobrovaitė B.
Published: March 2009

Yttria-stabilized zirconia (YSZ) coatings were synthesized using dc magnetron sputter deposition of Y/Zr layers followed by thermal treatment in the range of temperatures 600-1000 °C at atmospheric pressure in air. The characterization of YSZ coating structure was carried out by X-ray diffraction. The secondary ion mass-spectrometry analysis was used for the recording of depth profiles of the most important elements in coatings and at interface. The conducted analysis showed that processes on the surface play a dominant role in the synthesis mechanism of YSZ coatings homogeneous in structure and composition during the thermal oxidation. The excess of surface thermodynamic potentials supports an intensive intermixing across Y/Zr layers with continuous supply of oxygen through the surface. Under highly non-equilibrium conditions on the surface, the adatoms are driven into grain boundaries of crystallites and result in high compressive stress in grains. The stress relaxation initiates the plastic flow of matrix material with incorporation of oxygen atoms. Thermally activated dislocation glide is considered as the dominant plasticdeformation mechanism in these materials.
Self-Assembled TPPS4 Nanostructures Revealed by Atomic Force Microscopy
Authors: Augulis R. , Snitka Valentinas , Rotomskis R.
Published: March 2009

Meso-tetra (4-sulfonatophenyl) porphine (TPPS4) is water-soluble tetrapyrrolic dye, which forms self assembled nanostructures  J-aggregates under appropriate conditions. It was shown, that such aggregates survive dried on the substrate. The spatial structure of TPPS4 Jaggregates formed in acidic aqueous solutions and dispersed on silicon substrates was analyzed by means of atomic force microscopy (AFM). The stripe-like structures were observed. The size of individual stripes ranged 4,5×40×(200-1000) nm (H×W×L). The width and height was almost the same for all stripes and independent upon the concentration of the solution, however the length was statistically distributed and the mean length increased with increasing concentration of initial TPPS4 solution. At higher concentrations such stripes stacked into thicker fibers containing 2-20 stripes. Such fibers branched and formed large bush-like structures sized up to several millimeters. According to experimental findings the model of mesostructures, formed by TPPS4 J-aggregates, was proposed.
Atomic Force Microscopy of Self-Assembled Nanostructures of TPPS4 on SAM Substrates
Authors: Augulis R. , Valiokas R. , Liedberg B. , Rotomskis R.
Published: March 2009

The adsorption of organic molecules on solid surfaces is one of the fundamental
processes for the development of molecular-based nanodevices. Here we focus on the adsorption and ordering of the TPPS4-based J-aggregates on silicon and gold as well as on self-assembled monolayer (SAM) surfaces. The SAMs used for the experiments were based on the chemisorption of thiol containing compounds onto gold. Long ω-substituted alkanethiols are spontaneously assembled on gold to form highly ordered and densely packed layers with controllable chemical and physical properties.
TPPS4 J-aggregates were dispersed on SAM surfaces, and on plain gold and silicon substrates for comparison. The dimensions of aggregates, measured by means of atomic force microscopy, varied depending on the type of substrate. Long stripe-like aggregates were flattened on the substrate surface, and the height and width of aggregates highly correlated with the polarity of surface groups. For example, the J-aggregates were narrower on hydrophobic substrates (with non-polar groups) and wider on hydrophilic substrates (with polar groups). These observations support the hypothesis, that TPPS4 forms .soft. cylindrical aggregates, that appear flattened on the substrate.
Cylindrical Aggregates of TDBC: Linear and Nonlinear Optical Properties Versus Morphology
Authors: Pugžlys A. , Hania P.R. , Didraga C. , Knoester J. , Duppen K.
Published: March 2009

The linear and nonlinear optical properties of pure 3,3'-bis(3-carboxypropyl)-5,5',6,6'- tetrachloro-1,1'-dioctylbenzimidacarbocyanine (C8O3) aggregates as well as of C8O3 aggregates in the presence of PVA are studied at room temperature. The obtained results reveal that absorption spectra of both aggregates are governed by four absorption bands. Three of these represent transitions having dipole moments oriented parallel to the axis of the aggregate and one oriented perpendicular to it. The two lower energy parallel transitions are found to be weakly coupled which suggests that they represent two excitons located on different walls of the double-wall cylinder. In contrast, the lowest energy parallel transition and the transition having a transition dipole moment oriented perpendicular to the aggregate axis share the same ground state which reveals that they belong to the same exciton band. The manner of modification of the linear absorption with addition of PVA as well as the similarity of the pump-probe spectra of the two investigated aggregates suggests that this exciton band originates from the inner wall of the double-wall cylinder.
Dynamically Multivalued Self-Organisation and Probabilistic Structure Formation Processes
Authors: Kirilyuk A.P.
Published: March 2009

The unreduced, universally nonperturbative analysis of arbitrary many-body interaction process reveals the irreducible, purely dynamic source of randomness. It leads to the universal definition of real system complexity, where the internally chaotic self-organisation emerges as a characteristic case of complex interaction dynamics. One obtains the causally complete description of the world structure emergence, from elementary particles to consciousness, including practically
important and fundamentally substantiated propositions for self-formation research and applications.
Theoretical Modeling of TPPS4 J-Aggregates
Authors: Augulis R. , Tamulienė J. , Tamulis Arvydas , Rotomskis R.
Published: March 2009

The mechanism and conditions of meso-tetra (4-sulfonatophenyl) porphine (TPPS4) molecular aggregate formation and their geometrical structure are investigated by methods of molecular mechanics and quantum chemistry. J- type aggregates are formed of zwitterionic forms of TPPS4via interaction of their positively charged porphyrin rings and negatively charged SO3- groups. According to ab initio and PM3 calculations it was found that TPPS4zwitterion has asymmetrical structure (parts of porphyrin ring are asymmetrically bent out of plane), although the porphyrin ring of TPPS4molecule in neutral aqueous solution (at pH 7) is flat and the planes of phenyl rings are nearly perpendicular to the porphyrin plane. We propose that asymmetrical porphyrin rings are able to form bent threads. The thread is bent approx. 5° for each monomer, so approximately 60 monomers should form the loop (diameter ~20 nm).