Gaforex review journal newspaper
This transfer is preferably performed by an anisotropic etching techni- que. Anisotropic etch profiles are caused by the highly directional impact of ions onto the substrdte surface, but there are a number of basic facts to be considered in order to optimize the pattern transfer process for a given material or application.
While directional ion impact is responsible for the anisotropic nature of the etched profile, it can also cause redeposition of physically sput- tered material and be responsible for a deformation of the etch profiles due to faceting effects. Backscattering of sputtered species due to a small mean free path at the relatively high process pressure can cause a redistribution of etched material.
On the chemical side of the etching process, the profile shpae is influenced by the ease with which neutral species react with the material to be etched. While F atoms etch Si spontaneously which can lead to undercut profiles , C1 only reacts with Si to any extent when the surface is subjected at the same time to ion bombardment. Often, special tricks have to be played to protect the sidewalls of etched profiles from attack by neutral species. Etching of narrow and deep trenches into single crystal Si for the next generation of VLSI-chips is a typical example where a lot of basic knowledge was required to optimize the process.
Plasma etching in general can never be as selective as a purely chemical etching process because etching is always due to a subtle inter- play between chemical and physical effects and the non-selective physical effects can never be completely excluded. The parameter space in plasma etching is very large. Rate, anisotropy and selectivity often depend on subtle differences between etching systems.
This not only makes process development extremely difficult and often limited to a given piece of equipment, but it also makes it close to irpossible to study basic etching mechanisms on practical etching systems. Basic mechanisms, there- fore, have to be studied in special beam systems where not only the influence of ions and neutrals but also energy and flux of particles 'can separately be investigated.
An important consideration for device and circuit fabrication in addition to etch anisotropy, is whether the etching process introduces damage in the material or causes degradation in the performance of the devices. Energetic ions not only cause directional etching but devices subjected to ion bombardment can potentially also suffer from radiation damage.
Furthermore, practically every plasma etching process also causes a certain degree of contamination either due to plasma polymerization or redeposition of sputtered material from chamber walls, etc. Ion damage and contamination can be minimized by using optimal etching conditions and good chamber design. While more plasma etching systems used in manufacturing today are either single wafer parallel plate etchers or multi-wafer reactive ion etchers, there are currently a number of very promising techniques under closer investigation for possible use in production: Magnetron etching, microwave etchers in a variety of configurations, reactive ion beam etching or ion beam enhanced chemi- cal etching.
In addition, future etchers might also offer etching at a variable substrate temperature. So far, the only substrate temperature control which is used in industry is wafer cooling in order to prevent resist melting. But some recent publications indicate that temperature might be another real process parameter which so far has not been fully utilized. Irving, S. Claassen and V. Rutten Ned. These layers are usually made in capacitively coupled reactors operating at frequencies between 50 kHz and 20 MHz.
The compositional and structural properties of layers deposited in these types of reactors, depend, among other things, on the plasma parameters used. Due to electron impact on relatively stable molecules, active species, such as ions, excited molecules and radicals are formed. In these low pressure plasmas the mean electron energy is around 2eV, while the electron concentration is about cm- 3 3.
Confinement of the electrons near the electrode by using magnetic fields leads to an increase in the collision probability between electrons and reacting gas molecules. The influence of applying a magnetic field to a glow discharge on the layer properties has been studied recently 4.
Besides electron cyclotron resonance ECR CVD methods a number of authors have studied remote plasma exci- tation and microwave-sustained plasma techniques to be used in the production of thin layers 5. Dlasma silicon-nitride layers and, on a smaller scale, silicon-oxynitride layers are used for final passivation, because these layers act as barrier against diffusion of impurity ions such as sodium 6.
Furthermore, heat treatments after deposition could lead to cracks in the films, notably at steps. The search for a layer which could be used for final passivation as well as for multilevel insulation has led to study plasma silicon-oxynitride layers 8,9. Incorporation of oxygen in the film, which can be achieved by adding N2 0 to a SiH 4 -NH3 -N2 mixture leads to a strong decrease of the mechanical stress and to a reduction of the hydrogen content.
As discussed above the various deposition parameters such as plasma condi- tions, temperature, pressure and gas phase composition largely influence the compositional, the mechanical and the electrical layer properties. We will dis- cuss in detail the effect of the deposition parameters on layer properties of silicon-related compounds as deposited in capacitively coupled reactors.
Both alterations seem to have an positive effect on the film quality and will, therefore, be treated. Furthermore, topics such as film densification, layer adherence and silicon- oxy nitridi aluminium interactions will be discussed. The film properties of layers deposited in capacitively coupled reactors and of layers deposited in the microwave-, remote and ECR based reactors will be compared.
References 1. Reinburg, J. Rosler and G. Eagle, Solid State Technology, 22, 88 See for example: B. See for example: M. Leahy and G. Kanowicz, Solid State Technol. See for example: I. Kato, K. Noguchi and K. Numada, J. Sinha, H. Levinstein, T. Smith, G. Quintana and S. HasiTo, J. Claassen, Plasma Chemistry and Plasma Processing, 7, Chu, S. Sachdev and P. Extended Abstracts, J. Claassen, H. Goemans and A.
Kuiper, J. Flamm, C. Change, 0. Ibbotson and J. Mucha, Solid State of Technology, 3, 43 However, the other side of the coin is that plasma operations usually have hazardous feed gases and chemical effluents as necessary parts of the pro- cess. Etching chemistries that rely on chlorine as the basic etchant species have particularly hazardous consequences.
Deposition of materials from organo-metallic compounds should also have the utmost regard given to safe operation. The use of hazardous agent concentrating devices, such as cold traps and cryo-pumps should be avoided. Suggestions will be given on the method that may be used to define the plasma process configuration that pays the highest regard to safety for both the opera- tor and the environment. Examples of real plasma processes will be illustrated that were discontinued, in spite of their utility, because of the unacceptable safety risk imposed by their continued operation.
Greene Department of Materials Science, University of Illinois West Springfield, Urbana, Illinois, USA Low-energy eV ion bombardment of films during growth from the vapor phase plays an important and sometimes dominant role in controlling the growth kinetics and physical properties of films deposited by a variety of tech- niques such as glow discharge and ion beam sputtering, primary-ion deposition, molecular beam epitaxy utilizing accelerated beams, and plasma-enhanced chemical vapor deposition.
During nucleation and the early stages of film growth on amorphouse sub- strates, recent experiments carried out in UHV show that low-energy ion irradia- tion can lead to a more uniform distribution of islands, larger average island sizes, and an inhibition of secondary nucleation.
Ion bombardment during deposition is often used to modify film micro- structure. Depending upon the growth temperature, deposition rate, and colli- sion dynamics, ion irradiation can either increase or decrease the defect concentration in as-deposited films. Experimental results from both poly- crystalline and single-crystalline films will be used in conjunction with Monte Carlo and molecular dynamic simulations to discuss mechanisms leading to irra- diation-induced film growth effects such as densification, the controlled alteration of dislocation densities, grain size, and preferred orientation, the interruption of columnar structure, and epitaxy.
Ion irradiation has also been shown to dramatically alter the chemistry of growing films and results will be discussed in terms of, depending upon the materials system and deposition conditions, preferential sputtering of alloy constituents, collisionally-induced dissociative chemisorption, and trappirl processes. Examples of the latter case include the large increases in elemental incorporation probabilities, up to 8 orders of magnitude, and profile abruptness reported for accelerated-dopar,,s in MBE Si.
Mattox Surface and Interface Technology Division - Sandia National Laboratories, Albuquerque, NM In certain types of thin film deposition processes weakly ionized plasmas are used to enhance or enable the deposition process. These processes include: sputter deposition, ion plating, activated reactive evaporation, plasma poly- merization and plasma enhanced chemical vapor deposition PECVD. Bombardment may also enhance reaction of adsorbed reactive species with the sur- face and depositing atoms.
A weakly ionized plasma "processing plasma" is characterized by being a non-equilibrium plasma having a large fraction of un-ionized species. These un- ionized species may influence the deposition process by providing a high flux of species to the substrate surface throughout the processing.
The plasma may be sustained by the input of DC, RF or microwave energy and the electrons in the plasma may be influenced by a magnetic field in some cases "magnetron processes". Plasma-surface interactions generate a plasma sheath that accel- erates low energy ions to surfaces giving a cleaning mechanism which may be termed "ion scrubbing".
In the plasma, various collision and attachment processes give rise to a spectrum of chemical species which may deposit on surfaces or be available to react with depositing species. The film deposition chamber may be the same chamber as the plasma chamber or it may be separate from the plasma chamber, relying on the long lifetime of "activated" or ionized gaseous species to allow them to be transported.
In the plasma environment high energy electron, ion and neutral bombardment may be intentional or unintentional, controlled or uncontrolled. The particles may be accelerated to the surface "biased surface" or may be accelerated in- dependen6 of the substrate surface by appropriate grid and electrode systems.
In the case of ion bombardment of a surface at a low pressure reflected high energy neutrals may be an important source of energetic particles. In DC diode physical sputtering electrons and negative ions may be accelerated away from the cathode to give high energy particles that bombard the substrate.
High energy electron bombardment may be used to heat a surface. High energy ion bombardment may be used to heat the surface, remove surface material by the momentum transfer process of physical sputtering or by chemical reaction and vaporization from the surface "chemical sputtering". Energetic pdrticle bombardment during film deposition may promote reactive deposition pro- cesses when using reactive species or modify the properties of the deposited film material.
Some of these properties are very sensitive to the energy and flux of concurrent energetic particle bombardment. Many of these properties are interdependent. Species to be deposited in the plasma environment may originate from the sputtering process sputter deposition , from thermal vaporization, arc vapori- zation or from gaseous chemical species introduced into the plasma chemical ion plating, PECVD.
The species and energy of the bombarding species, nature of the adsorbed species and the ratio of the flux of bombarding energetic particle to the flux of depositing particles are important process variables in film deposition pro- cesses performed in a plasma environment. The main classes of monomers generating the various types of films will be listed.
More emphasis will be given to fluorine containing polymers, organosi- licons, metal-polymer c,nposites and hydrocarbons. All these classes of films will be considered as individual case studies by trying to define the mechanism of polymerization and the parameters affecting the chemical structure, the cross-linking density and the properties of the films. In particular, it will be shown the effect of the discharge frequency, reactor geometry, superimposed magnetic field, substrate bias, substrate temperature, power input, and pressure.
An effort to draw general trends will be made. The review will conclude with a section on plasma polymer applications. This part will be subdivided into a section on applications in which the surface is of primary importance and one in which the bulk properties of the film is the determining factor. Almeida, F. Guimaries, M. Ramos Universidade de Minho Laborat6rio de Ffsica P BRAGA Codex The authors have for some time been involved in the design, fabrication and use of DC magnetron sputter coating systems for research purposes, some of which have previously been reported.
This presentation is concerned with the physical characterization of the discharge plasma in one of those magnetrons, in order to improve the design of future versions. The magnetron is of the planar type, with circular symmetry, and uses a DC voltage of a few hundred volts to sustain a discharge in an atmosphere of argon at a pressure of around 4x10 "2 torr, assisted by a magnetic field created by a permanent magnet. In order to characterize the processes in the magnetron, the distribution of the magnetic field has been measured and so have several parameters of the discharge.
By means of single and double electric probes, the authors have measured the potential distribution and the density of charged particles and have drawn conclusions in respect of the speed distribution of electrons in the plasma. The results of the experiment are show in the body of the presentation and are used to recommend improvements for the future magnetron designs.
In this situation, the electron energy distribution function e. The kinetic model that determines the densities of the plasma spe- cies is coupled to the e. The dependence of these densities on the experimental parameters is studied. The influence of the main processes, volume ones and those involving plasma walls is emphasized. A comparison of the results of the modeling with experimental ones is attempted through the analysis of the spectra of Balmer lines.
Probe techniques are implemented to control the plasma parameters. An important application is the measurement of ion velocity distribution functions. A tunable dye laser is pointed at a plasma and its frequency is scanned while observing fluorescence. Ideally, the fluorescence signal plotted versus frequency would give a direct measurement of the distribu- tion function as a result of doppler broadening; however, several additional mechanisms broaden the spectral line.
The resonance width of the excitation transition in the LIF scheme will always be a factor. When a laser with more than MHz bandwidth is employed, instrumental broadening must also be con- sidered, and when a powerful pulsed laser is used, saturation broadening must be taken into account.
A method of data analysis for determining the ion distribution function is described. The LIF signal for a set of plasma and laser parameters is computed, including all the broadening effects, and plotted against frequency. The experimeter selects a set of plasma parameters, compares the resulting com- puter calculation to his data, and then iteratively adjusts the plasma parame- ters until the calculated curve fits the data. Hartney Dept. A reactor built in our laboratory is equipped with a quadrupole mass spectrometer and a cylindrical mirror analyzer which allows measurement of the ion energy distribution during etching.
In addition, the mass spectrometer is used for species identification and to determine the extent of oyxgen dissociation in the plasma. The degree of dissociation was measured as a function of reactor pressure between 20 and 80 mtorr and input power between 0. Dis- sociation decreases with increasing pressure, while the etch rate of standard resists increases. In addition, ion energy and current decrease with increasing pressure, therefore the undissociated molecules are the- limiting species in etching under these conditions.
Experiments were performed to determine the contribution of ion induced damage to the etching of resists. The effect of damage is minimal for etching hydrocarbon resists, but it enhances the formation of an oxide layer when etching silicon containing polymers. Akkurt Process, characteristics, equipment, and procedures for electron and laser beam micromachining of solids will be discussed. M6hI Technics Plasma GmbH, D Kirchheim bei MUnchen In connection with the short talk about "A novel microwave ion beam-system for surface processing" this paper describes principles and practical applica- tions of ion beam milling and plasma etching.
The explanation are based on the exchange of experiences between the com- pany Technics Plasma GmbH and comoanies, which are using the plasma and the ion beam etching. One example is the ion beam milling of cadmium-mercury-telluride, which is patented in the USA and Germany. There will be given a summary of requirements for the production of semi- conductors for the conditions of rooms and climate, the changes in chemicals, the masks, the discs, the exposure and the development.
The necessity of new and revised methods is easily realized by the complicated structures of the microprocessors. The requirements and the data for the ion beam and the plasma-etching are given in tabulated summary. The quality of ion beam and plasma etching are shown by examples. There will be listed the different applications as for example: - Pre-treatment of glass, ceramic or semiconductor substrates to improve the adhesion of metal coatings or to improve bonding qualities.
In the talk this list will be completed. One important point will be the discussions about the collaboration between the groups of different countries. The oral presentation will be given by K. Markert, J. Noel, and J. Knall, M. Hasan, and J. Sundgren Linkoping University, Sweden Ion-surface interactions can change film growth kinetics dramatically. Our experiments using low-energy accelerated-dopants during Si MBE growth demonstrate increases in elemental incorporation probabilities by several orders of magnitude, improved control over concentration depth distributions, and substitutional incorporation at concentrations exceeding equilibrium solid- solubility limits.
These results stem from effects such as trapping and creation of preferential adsorption sites due to low-energy ion bombardment. Arefi, V. Andre, F. Tchoubineh, P. Montazer-Rahmati, J. Amouroux, M. Curie, PARIS Cedex 05 The surface treatment of polymeric films PP, PET has been realized in an installation in which a background pressure of 10 -4 Pa can be obtained in order to eliminate partly the adsorbed or condensed gases on the films.
The plasma treatment is carried out in NH3, N2 or Ar, and is meant to improve the adhesive properties of the film towards metallic coatings. The treatment process includes a hollow high-voltage electrode, parallel to the grounded cylinder on which the polymer film is enrolled. The rotational velocity of the cylinder 0. The industrial generator empl'. The control of the treated samples has been possible through methods of analysis including ESCA, contact angle measurements surface energy calculation as well as the structural analysis by TEM.
The analysis of the surface free energy is accomplished by the use of an image processing system which allows an automatic measure of the contact angle every 0. This process presents the advantage of obtaining the disper- sive and polar components of the surface tension with a speed compatible with the kinetic measure of the surface modification of the treated films.
The measurements show an increase of the dispersive component of the surface tension for treatment times below I second, that is to say for the treatment for which no nitrogen moities have been detected by ESCA analysis in the case of plasma treatment in NH3 and N2. The understanding of the aging process of the samples has been possible with the help of the contact angle method. This method is more appropriate for the analysis of the surface properties, than ESCA, particularly to appreciate the evolution of the dipoles and the surface free energy.
The future analysis will be related to the study of the structure of the metals which are deposited onto the pretreated surface as well as the nature of the njetal-polymer interface; this will be possible with methods such as Auger, ESCA and TEM. Androulidaki, P. Tzanetakis, Y. Fragiadakis F. The hydrogen content and bonding in the films was determined by IR spectro- metry and their optical and photoelectronic properties were measured. The growth rate was found to increase drastically with Ge content.
An attempt is made to clarify the role of plasma etching during growth in this system. Bensaoula and A. The principal mechanism responsible for the etch is found to be defects present near the surface of the films and the enhancement under inert gas ions is mainly due to damage generated by these energetic par- ticules. A model of the etch will also be presented. Bonanno, M. Camarca, R.
Bartucci, L. Sportelli, E. Balestrino, S. The partial orientation of paramagnetic complexes previously observed, is computer simulated. As a result of the simu- lation the less abundant cupric component gives the largest signal in the g region.
Actually, the less abundant cupric complex, Cu 1 , has a rectangular planar environment characterized by rows of oxygen atoms along [] directions and by rows of oxygen atom vacan- cies along [] directions. The most abundant, Cu 2 ion site has, instead, a pyramidal oxygen-coordination. Since theoretical considerations suggest that copper oxygen planes are responsible for the superconductivity while copper-oxygen chains may not be essential, we tried to distinguish between the two contributions versus temperature in Electron Paramagnetic Resonance EPR spectra.
Of course, the variation of the transition probability with the g-value is considered, while the magnetic hyperfine orientations of the z- axis of the paramagnetic microcrystals with rspect to the magnetic field, but a partial orientation of paramagnetic complexes was necessary to reproduce the experimental data.
On the other hand, also angle-resolved EPR measurements [3] on pellets show an angular dispersion of some features. In the insert it is reported the calculated powder EPR spectrum dashed line , that is the envelope of line shapes from random oriented paramagnetic microcrystal axes with respect to the magnetic field. Since a large number of bondings lie in the plane perpendicular to the z-axis of the unit cell, we expected a stroing signal in the g region as actually occurs, but the present analysis show that it comes essentially from the less abundant Cu 1 cupric component.
Both absorptions, instead, contribute in the g-region. In conclusion, the computer analysis revealed the existence of oriented domains in YBa2Cu3O 7. References 1 T. Siegrist, S. Sunshnia, D. Murphy, R. Cava and S. B 35, Bartucci, E. Colavita, L. Sportelli, G. DB 37, Camarca, A. Bonanno, R. Colavita, G.
Barbanera, in preparation. By introducing a scaling similar to that used in multiple scattering, and assuming that inhomogeneities are small compared to the mean thickness we can obtain an expression which results independent of the ion, ion-energy, and target specie and inhomogeneity. Comparisons with previous Monte Carlo calculations show excellent agreement. Analysis of experimental results, in cases where information of the target in- homogeneity area available, indicate that, although not all angular variations are caused by inhomogeneities, there are cases where they can, to a great extent, be contributing to the mentioned effect.
It must be thus concluded that, in experiments of this kind, an estimation of the target inhomogeneities should be necessarily included. Arista, G. Lantchsner, J. Eckardt, and M. Bohr, Mat. Copenhagen, 28, No. Besenbacher, J. Andersen and E. Bonderup, Nucl. Epaillart and J. Bretagne and A. Ricard Laboratoire de Physique des Gaz et des Plasmas, Universite de Paris-sud, ORSAY France Multifunctional acrylates can be polymerized under a cold plasma treatment when the monomer is spread on a substrate and subjected, for example, to a tetra- fluoromethane plasma.
The generator used in this study is a micro-waves genera- tor Mhz. The polymerization rate and the resulting polymer structure are related to the conditions of plasma generation. A mechanism is proposed from comparison between the excited species concentrations in the gas phase, at the polymer surface and the concentration of CF2 groups bound to the polymer skeleton at its surface and in the bulk.
Filius Interfaculty Reactor Institute, The Netherlands In nuclear fusion reactors and other plasma devices ions escaping from the plasma may release molecules that are adsorbed at the surfaces of construction materials. The released molecules can interact with the plasma and may thus have a considerable influence on the plasma characteristics. Hydes, T. Cox, D. Hope and V. It has become evident that, in order to alleviate this problem and so facilitate the process transfer between different machines, it is necessary to fully characterize the plasma system.
We have cooceptually divided this into two tasks 1 to characterize the glow dis- charge, and 2 the glow-sample interface characterized by the D. For these R. The glow can be characterized from a knowledge of the partial pressures of ground state species and the electron energy distribution function, as measured by a Iangmuir probe LP.
This is, however, an invasive technique and is not simple to operate. Optical emission spectroscopy OES on the other hand, is non-invasive, simple to run and has been shown, in our studies of Argon plasmasl, to yield corrobative and comple- mentary information on the electron energetics of the plasma. We have used our diagnostic techniques of OES, to assay the glow discharge, and a LP and a voltage probe to characterize the DC bias, in order to try to set up the same plasma in two very different etching machines.
The purpose was to determine whether a dry etch process could be transferred between etching machines by the physical characterization of the important plasma parameters. The process studied was the etching of polyimide by an oxygen RIE plasma and the one response of the process to be transferred was the anisotropy of features etched in the polyimide through a thin IOOA non-erodable aluminum mask.
Our results demonstrate that a dry etch process can be successfully trans- ferred between two different etching machines using the plasma characterization method, which should be applicable to other more complex systems. It is import- ant to note, however, that the LP measurements showed that the plasmas in the two machines were markedly different in respect to electron densities, and that these scaled approximately with the magnitude of the etch rates in each machine.
This fact, together with the observation that our optical fingerprinting tech- nique is insensitive to plasma density, suggests that, although we set up simi- lar plasmas in the two etching machines, they differed in the absolute magnitude of the concentration of species. Pech and A. Universite Paris-Sud Batiment ,. In order to characterize the discharge conditions prevailing at various selected magnetron current values Im up to 4 A , the currents flowing into the substrate, as well as into the grounded guard ring around it, and into the grounded rotatable shutter have been simultaneously mea- sured during the runs.
The experiments have been carried out with the substrate being either grounded or negatively biased up to 0C , and at variable tem- peratires up to 0 C. Analysis of the currents measured at the various locations reveals predomi- nantly electron or ion currents flowing into the various electrodes, according to the prevailing experimental situation.
The correlations found between the variations in nature and in magnitude of these currents on one hand, and the variations in space and in magnitude of the emission intensities, on the other, suggest that the electron density ne distribution in the inhomogeneous plasma in the vicinity of the substrate and farther away from it undergoes considerable modifications according to the variable experimental parameters.
It turns out that the reduced The so reduced intensity values obtained at 15 mm from the substrate for the various Im values are practically independent of the other largely variable ex- perimental parameters. It seems that consideration of similar reduced emission intensity values may find a more general, justification for sputtering systems where the presence of grounded parts in the vicinity of the substrate leads to substantially modified ne distributions for variable experimental situations.
Munduate Plasma spraying technology can be considered as a development of traditional thermal spraying methods. This technique has made it possible to deposit a large variety of materials onto different substrates in an economical way. In this paper the process and equipment are briefly described. Most of the work reviews some interesting applications of this technique. These include thermal barrier coatings made of ceramic materials TBC for engine components.
The materials and structures of such coatings are analyzed. The properties of the coatings in relation to the problems found in service conditions are described. Finally, some laboratory experiences showing the thermal shock resistance of the coating are described.
In tiis work the ion beam is generated in a Kaufmann source and the ion energy may be varied between and eV. The positive ions emitted from the bombarded samples are energy and mass analyzed using an electrostatic energy analyzer followed by a quadrupole mass filter. This system allows observation of positive ions formed in three ways: i By ionization of background gas molecules caused by collision of background molecules with energetic ions in the primary beam.
The observed energy of these ions gives a measure of the potential at the point of formation in the ion beam. This yields information on the products of. If noble gases are added to the source then the energy spectrum of these scattered ions e. The ions generated by the three mechanisms are found to have different energy distributions which therefore allows the separate observation of these three groups of ions.
These results will be discussed in terms of a model for the fluorocarbon RIBE of tungsten. Sliwinski Polish Academy of Sciences, Institute of Fluid-Flow Machines, Poland A high-power facility for investigations of laser supported plasma-surface interaction is presented with particular attention to the experimental potential of two independently driven processing stands, i.
Results of plasma-surface intereaction experiments are discussed. De Puydt, B. Lutgen DuPont de Nemours s. L Luxembourg, G. The corona treatments have been performed in different atmospheres including nitrogen, ammonia and air. XPS has been used to investigate thc chemical modifications occurring at the PET surface after these corona treatments. XPS results show that nitrogen incorporation takes place as non-oxygenated nitrogen functionalities, like amine or cyano groups. These are present at the surface of all the corona treated samples, but in different concentrations depending on the gases used in the corona discharge.
Furthermore, XPS analyses performed after heating of the treated samples show a higher thermal stability of the corona induced surface modifications in the case of nitrogen and ammonia. ISS and statis SIMS analyses have also been performed due to their higher surface sensitivity as compared with XPS: ISS reveals that nitrogen is not pre- sent at the top most surface layer of the treated samples but is incorporated just beneath.
At the top surface, the samples present an oxygen rich com- position. Finally, static SIMS spectra show that corona treatment induces more pronounced surface degradation when performed in air than when in nitrogen or ammonia. These results are discussed in relation with adhesive properties of PET. Climent-Font, J.
Perriere' and A. Straboui We have shown the possibility of growing thick oxide films on refractory metal silicides by plasma oxidation in the to 0 C temperature range. The composition and oxide thickness, and the oxide growth rate were deter- mined by the complementary use of nuclear reaction analysis and RBS which was also employed to obtain the depth distribution of cations in the oxide, and the changes in the stoichiometry of the silicides.
We have found that the plasma oxide growth on silicides can be schematically described by a two-step process. These SiO 2 metal free films on the WSiy films are formed by Si atoms in excess in the sili- cide 'intil the composition WSi 2 is reached. The nature of the substrate, that is Si or SiO 2, does not seem to have any effect.
Dengan demikian, Indonesia menjadi negara dengan populasi umat Muslim terbesar dalam hal keagamaan. Negara no 1 paling pemurah didunia Indonesia sedang di urutan kesatu sebagai negara paling pemurah di dunia. Laporan tersebut menyuguhkan negara. Tiga skor tersebut menjadi parameter pemeringkatan.
Dikutip dari international. Indonesia peringkat kesatu soal jumlah perempuan yang bekerja Berdasarkan keterangan dari seorang CEO asuransi terkemuka dunia asal Jepang bernama Haruaki Deguchi, Indonesia menduduki urutan kesatu negara yang paling tidak sedikit pekerja wanitanya. Hal ini mengindikasikan wanita di Indonesia lebih dapat mandiri, namun peranan laki-lakinya jadi kalah pamor.
Indonesia juara dalam pemusnahan Illegal Fishing Terlepas dengan gayanya yang nyentrik dan kontroversial, namun kiprah Menteri Susi Pudjiastuti memang pantas diapresiasi. Langkah-langkahnya paling nyata dalam mereduksi sekian banyak hal buruk, salah satunya ialah fenomena pencopetan ikan oleh kapal asing.
Seperti yang anda tahu, ibu dari si cantik Nadine Kaiser ini tak segan membenamkan atau meledakkan kapal pencuri. Hasilnya ternyata dominan luas. Pencuri kian segan dan Indonesia diganjar penghargaan membanggakan. Ya, sejumlah waktu kemudian Indonesia diserahkan penghargaan sebagai negara nomor satu yang sangat aktif memberantas pemerasan sumber daya laut.


Think, the place between our bodies movie online apologise, but
HOW DO YOU SELL ETHEREUM
Viewer for Windows: your mobile phone or tablet for. All you need indicates that it. By default, where as IE8 users up each change enable this setting, event of.
4 комментарии к “Gaforex review journal newspaper”
Shakagore
on18.07.2021 в 11:41 говорит:
btc all-comers indoor track meet
Samut
on19.07.2021 в 14:21 говорит:
warren buffett investing formula
Kalar
on19.07.2021 в 15:47 говорит:
how to make a cryptocurrency pool
Arashirisar
on21.07.2021 в 23:20 говорит:
forex prekyba lietuvoje ziemojantys