Top PDF Mechanical characterization of thin films with application to ferroelectrics

Mechanical characterization of thin films with application to ferroelectrics

Mechanical characterization of thin films with application to ferroelectrics

One important part of the motivation for this research work comes from the microelectromechanical systems (MEMS) technology. Its basic concept of high volume production and low unit cost can only be achieved when the devices made by microelectronics technique are reliable. The success in this area largely depends on the understanding of materials. However, the mechanical characterization is lagged behind the theoretical work and designing software development. The standard characterization method is still not established. For MEMS actuators, especially for active materials, the desired characterization system for obtaining mechanical properties requires load control feature and the capability of doing dynamic tests. However, there is no such method among the currently available tools for mechanical characterization.
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Mechanical characterization of nanostructured thin films at different scales

Mechanical characterization of nanostructured thin films at different scales

Due to interesting characteristics, such as flexibility and low thickness, thin metal films on polymer substrates are becoming increasingly used in many technological applications such as stretchable microelectronics [1-2], polymer metallization [3] and aeronautics. Enhanced properties can be obtained by combining different materials in form of nanostructured thin film [4]. In particular, tungsten-copper (W-Cu) composites show very important mechanical properties resulting from the compromise between the high strength of W and the ductility of Cu [5-7]. Owing to the specific fabrication, nanoscaled materials present physical properties which are different to bulk counterparts [8] and are subjected to high stresses that can lead to the formation of damages such as cracks and surface delamination in the case of metallic films. Thus, understanding the mechanical behaviour of nanostructured thin films is of utmost importance for ensuring the reliability of systems. Amongst specialized techniques for mechanical characterization of supported thin films, in-situ tensile testing has been proven to be the most suitable method [9-16]. Uniaxial testing commonly used generates a non-equi-biaxial state in the film due to Poisson’s ratios mismatch between the substrate and the metallic thin film. As described and validated in a very recent work [17], the new biaxial tensile machine, which has been developed for DiffAbs beamline at SOLEIL, the French synchrotron facility (Saint Aubin), allows for testing in both equi-biaxial and non-equi-biaxial loading conditions, mimicking in a more realistic manner the complex stress state applied to nanostructured systems during service in many application fields. Noticeably, bulge and ring on ring tests can be used to investigate the behaviour of thin films under plane stresses [18-19]. Due to the thermal expansion mismatch between film and substrate, a biaxial stress state can also be applied to the film © Owned by the authors, published by EDP Sciences, 2010
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Evaluation and Characterization of Thin Films on AISI 9840 by Electrochemical Noise

Evaluation and Characterization of Thin Films on AISI 9840 by Electrochemical Noise

In recent years, the number of components used in the process of wear resistance has increased considerably, which is the reason that the hard coatings play an important role at the industry, the coatings increase the life time of the tool and in many cases, properties typically achieved can not be obtained by bulk such as: high hardness, low friction, wear resistance and high corrosion resistance. [2] A wide variety of materials can be applied by sputtering, this technique need to cover almost any coating. Aluminum and chromium are among the materials most widely used at deposition and are gradually replacing cadmium in corrosion applications [3-5]. The mechanical characteristics of the Al layer can be strengthened by the addition of transition metals such as chromium. [6]
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RF plasma synthesis and characterization of thin films for transparent conductors

RF plasma synthesis and characterization of thin films for transparent conductors

cm -3 and ideally a resistivity <10 -3  cm. They are highly transparent in the visible region and highly reflective in the near infrared, where the so-called free carrier absorption takes place. In general, TCOs are polycrystalline, although, recently, studies on amorphous TCOs have also been performed [2]. The degree of crystallinity (grain size) influences the electron transport, i.e., better crystallinity (larger grains) leads to higher film conductivity. Each of the application already mentioned in Chapter 1 have different requirements upon the optoelectronic and structural properties of TCO film. For example, for some applications amorphous films are desired because they are normally easier to etch and smoother than the polycrystalline films [2]. Therefore, a profound understanding of the fundamental aspects of transparent semiconductors is required in order to improve either the properties of existing materials, or design new type of TCOs.
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Synthesis and Characterization of Polypyrrole (PPy) Thin Films

Synthesis and Characterization of Polypyrrole (PPy) Thin Films

gated and new application fields have also been explored in the past several years. For example, PPy-based poly- mers can be used to load and release drugs and bio- molecules [15]. PPy-based polymer blends can protect the corrosion of metals [16].

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Dynamic mechanical properties of bio polymer graphite thin films

Dynamic mechanical properties of bio polymer graphite thin films

black, opaque and has a lustrous black sheen. It is unique because it has the characteristics of both metals and non-metals. It is flexible but not elastic, has electrical conductivity [6] and high heat, and very refractory and chemically inert. It has a low adsorption of X-rays and neutrons making it a useful material in nuclear application [7].

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Synthesis and Electrical Characterization of ZrO2 Thin Films on Si(100)

Synthesis and Electrical Characterization of ZrO2 Thin Films on Si(100)

for complementary application of metal oxide for using in semiconductor technology. Several oxide materials with high dielectric constant have been investigated as an alter- native gate dielectric. However, their application is limited due to the interfacial reaction between dielectric materials and tradition microelectronic substrates, such as Si sub- strates, during the post annealing processes are known va-

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Structural Characterization Of HgSe2 Thin Films By Electrochemical Route

Structural Characterization Of HgSe2 Thin Films By Electrochemical Route

In recent years there is a lot of attention due to its application in the fabrication on the thin films for the transition metal chalcogenides. (Chopra et al., 2004) Researchers are realising on the application of this transition metal chalcogenides into the efficiency of its conversion of sunlight to electricity. The semiconductor chalcogenides in thin film technology has been developing in the photoelectrochemical (PEC) cells applications.

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Surface Functionalisation and Characterization of Diamond Thin Films for Sensing Applications

Surface Functionalisation and Characterization of Diamond Thin Films for Sensing Applications

Diamond possesses such out standing properties that its exploitation in many fields is desired and sought for several years now. It is famous among scientists for its combination of exceptional physical and mechanical properties such as high thermal conductivity, chemical inertness, optical transparency (from UV to IR), high me- chanical stability and corrosion resistance. Due to its indirect optical band gap of 5.47 eV, diamond belong to the group of wide band gap semiconductors. It has a crystal structure identical to its more common relatives silicon and germanium. On first glance one might also expect similar surface properties in terms of reconstruc- tions, surface states, and surface band diagrams. In part, this expectation is indeed fulfilled, but diamond also exhibits a number of unusual and potentially very useful surface properties [1, 2]. When the surface dangling bonds of diamond are saturated by monovalent hydrogen atoms, (donor-like) surface states are removed from the gap, the electron affinity changes sign and becomes negative and the material becomes susceptible to an unusual type of transfer doping where holes are injected by accep- tors located at the surface instead of inside the host lattice. The negative electron affinity is used to fabricate cold cathode, while the diamond surface conductivity allows to use diamond as an electrode to collect electrical signals [3, 4].
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Fabrication and Characterization of Magnetostrictive Amorphous FeGaSiB thin films

Fabrication and Characterization of Magnetostrictive Amorphous FeGaSiB thin films

Recently, the development of magnetic amorphous materials has become of interest for Micro- Electro-Mechanical (MEMS) application such as low field sensing applications [1,2]. One of the main materials of interest is magnetostrictive Fe-based amorphous thin films, such as FeSiB (Metglas). Thin films with amorphous structures have an absence of atomic long range order, thus they only have a random short range order, which leads to magnetocrystalline anisotropy coefficients of zero [3] compared to crystalline thin films. In this case, the magnetic properties of these films can be affected by magnetoelastic anisotropy and shape anisotropy [3], such that large magnetic anisotropy can be generated by inhomogeneous strains within the amorphous alloys [4]. Due to their amorphous structure, FeSiB thin films [5] can be magnetized and demagnetized quickly using a low applied magnetic field (<40 kA/m). Thus reducing the saturation field, while maintaining/increasing the magnetostriction constant of amorphous thin films is of interest to produce new low field sensing thin films.
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Preparation and Characterization of Silica/Polyamide imide Nanocomposite Thin Films

Preparation and Characterization of Silica/Polyamide imide Nanocomposite Thin Films

Silica nanoparticles as a very important inorganic material have emerged as an area of intense current interest motivated because of their special physical and chemical properties, such as their small size, strong surface energy, high scattered performance, and thermal resistance [19–23]. However, the applications of silica nanoparticles are largely limited because of their high energetic hydrophilic surface, which causes the silica nanoparticles to be easily agglom- erated. Fortunately, this problem could be resolved by using some surface modification methods with different surfac- tant agents. In other words, the strong interface adhesion between the organic matrix and silica nanoparticles is a key to the application of silica nanoparticles as fillers.
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Characterization of Nanostructure Lead Selenide (Pbse) Thin Films

Characterization of Nanostructure Lead Selenide (Pbse) Thin Films

ABSTRACT: With Reduction In Size, Novel Electrical, Mechanical, Chemical, Magnetic, And Optical Properties Can Be Introduced. The Resulting Structure Is Then Called A Low-Dimensional Structure (Or System). The Confinement Of Particles, Usually Electron S Or Holes, To A Low- Dimensional Structure Leads To A Dramatic Change In Their Behavior And To The Manifestation Of Size Effects That Usually Fall Into The Category Of Quantum-Size Effects. The Low Dimensional Materials Exhibit New Physicochemical Properties Not Shown By The Corresponding Large-Scale Structures Of The Same Composition. Nanostructures Constitute A Bridge Between Molecules And Bulk Materials. Suitable Control Of The Properties And Responses Of Nanostructures Can Lead To New Devices And Technologies. Lead Selenide Thin Films Were Successfully Prepared Varying Ph By Chemical Bath Deposition Technique On Glass Substrates. The Variations Were Found To Affect Thickness Of The Deposited Films. The Structural And Electrical Properties Of The Films Were Found To Be Thickness Dependent. The X-Ray Diffraction Studies Revealed That All Films Had FCC Crystal Structure With A (111) Preferred Orientation. Optical Studies Indicated That The Band Gap Decreased With Increasing Thickness Of The Films. The Electrical Conductivity Decreases With Thickness While The Dielectric Constant Increases With Thickness
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Synthesis and Characterization of Cobalt Oxide and Composite Thin Films

Synthesis and Characterization of Cobalt Oxide and Composite Thin Films

atmosphere from 450°C during heating or at the beginning of the cooling phase. Composite films with different phase ratios could be obtained, depending on the temperature for changing from inert to oxidizing atmosphere. Both the heat-treatment atmospheres and the film thickness, which decreases with increasing spin velocity and with decreasing concentration of the precursor solution, were found to be important parameters in controlling the phase ratios of the films. The results open for tailoring of chemical and physical properties through control of thickness and phase compositions in cobalt oxide and composite films. This is interesting for practical application such as catalysis, as well as for fundamental
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Characterization of Thin Films by Low Incidence X Ray Diffraction

Characterization of Thin Films by Low Incidence X Ray Diffraction

Clearly, independent measurements should be used in order to verify the reliability of the presented procedure, and possibly standardize a correction or scaling factor for a range of thickness values. Along this line, our GAXRD results for cadmium selenide (CdSe) films of sub micro- metric thickness (electrodeposited on Ti or Ni electrodes by various electrolysis charges) were found to be in fair agreement with stylus profilometry measurements, namely, within an accuracy of 50 nm (unpublished results). Else- where also [1], application of the above model has been shown to give results in consistence with other mea- suring techniques.
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Structural and Electrical Characterization of GaN Thin Films on Si(100)

Structural and Electrical Characterization of GaN Thin Films on Si(100)

GaN (Gallium Nitride) have attracted interest due to their wide and direct band gap and their potential application to blue-ultraviolet light emitting devices, short-wave- length optoelectronic devices and high-power electrical devices [1]. Silicon is increasingly being used as a sub- strate for GaN growth [2,3] GaN deposited on silicon (Si) substrates has great advantages including excellent wafer quality, less hardness and more design flexibility with current silicon electronic circuit system [4-6]. The Si substrate for GaN growth has some advantages over other substrates. It can be obtained at low cost and the well developed Si growth technology ensures high qual- ity p- and n-type Si wafers. Furthermore, the het- ero-epitaxial system of GaN on Si substrate can poten- tially combine the optoelectronic properties of GaN with those of highly advanced Si electronic devices. Direct growth of a GaN film on Si substrate results in either polycrystalline growth or a substantial diffusion of Si into the GaN film. Direct growth of a GaN film on Si substrate results in either polycrystalline growth or a substantial diffusion of Si into the GaN film. Thin AlN films have been used as buffer layers for GaN growth on Si substrate [7,8]. Threading dislocations and inversion
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Optical and electrical characterization of ZnS:Sn thin films for solar cell application

Optical and electrical characterization of ZnS:Sn thin films for solar cell application

maintain alkaline solution at a pH of 9. When the deposition temperature reached 80±1°C, pre-cleaned glass slides were introduced vertically inside the substrate holder, dipped into the solution and left for deposition for 30 minutes. After completion of film deposition, the samples were removed from the beaker and allowed to cool. The deposited films were then rinsed with de-ionized water to remove soluble impurities and dried. The film samples were prepared at different tin chloride concentration ratios by volume. The deposition parameters are summarized in table 1.

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Micromechanical characterization of ALD thin films

Micromechanical characterization of ALD thin films

Annealing is a thermal treatment used for several purposes: to active dopants, to modify bonds of bonded wafers, to densify films and to reduce residual stress in materials. Annealing changes physical and chemical properties of thin films since annealing induces modification of film composition, reduction of pin-holes, increasing of grain sizes. Therefore, annealing influences the crystallinity and to the mechanical properties of materials. However, if thin film is deposited at temperatures comparable to the annealing temperature, then only minor residual stress changes can be observed after annealing. This is associated due to low thermal stress induced by annealing. For instance, LPCVD films have stable tensile stress during and after annealing. In contrast, if films are grown at lower temperatures than of annealing and have different expansion coefficients from a substrate, dramatic stress changes can take place. For example, the residual stress of PECVD silicon oxide films after annealing >800 °C become more compressive since the thermal expansion coefficient of silicon oxide is much lower than of silicon substrate (3.08 ppm/°C for silicon versus 0.55 ppm/°C for silicon oxide) and therefore the film is unable to shrink as much as silicon during cooling to room temperature, leading to compression of the film. If annealing of PECVD silicon oxide is performed at 500–550°C, then most of hydrogen and moisture diffuse out, and film can even experience tensile stress due to microstructure changes induced by hydrogen reduction from the film. PECVD silicon nitride films exhibit different behavior from PECVD silicon oxide upon annealing at temperatures >600°C due to very small difference of thermal expansion coefficients with silicon (the difference is only 0.8 ppm/°C). During the annealing, silicon nitride film losses hydrogen and stress rapidly changes from compressive to tensile and stays tensile after the cooling to the room temperature [98]. Figure 20 displays schematic representation of the mechanism of hydrogen loss in PECVD Si 3 N 4 film during annealing.
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Growth and Magnetic Characterization of High Manganese Silicide Thin Films

Growth and Magnetic Characterization of High Manganese Silicide Thin Films

There has been much interest in ferromagnetic semiconductors in recent years due to their application in the field of semiconductor spin transfer electronics (spintronics). Recent research in this field aims to use the increased spin degrees of freedom of charge carriers in semiconductors to increase the performance of electronic devices. Since traditional integrated circuits employ the charge in capacitors for memory storage, these ICs exhibit a volatile storage capability due to the loss of information when power is turned off or lost. Ferromagnetic materials, on the other hand, provide a non-volatile means of data storage. The addition of the spin degrees of freedom to the charge degrees of freedom in spintronic devices will provide the means for improved data processing speed, reduced power consumption and increased integration densities.
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Cu2ZnSnS4 thin films solar cells: material and device characterization

Cu2ZnSnS4 thin films solar cells: material and device characterization

However, an accurate and fine control of the film composition was an issue. Despite the film stoichiometry can be controlled by varying the metal proportions into the starting precursors, the growth method, with the available facilities, revealed some limits in terms of sample homogeneity, control and reproducibility of the process, thus making difficult to obtain fast improvements of the device performances. Despite the possibility for further development of CZTS thin films produced from staked precursors, the activities on these materials were stopped in 2012, to explore a new promising fabrication route, based on co-sputtered deposition of precursors. With the new process, adopted in a second stage of our activity after an upgrade of the deposition systems, CZTS thin films were grown by sulphurization of precursors obtained by simultaneous sputtering of the three binary sulphides: CuS, ZnS, SnS. The use of co-deposited precursors was already suggested in the literature as a promising strategy in terms of uniformity and control of material composition [72, 160], as all the elements necessary for CZTS phase formation are already present and homogeneously mixed in the starting film.
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High Quality Germanium Oxide Thin Films: Deposition and Characterization.

High Quality Germanium Oxide Thin Films: Deposition and Characterization.

The XAS O K edge spectra of films deposited on Ge and annealed at 400 C, have a band gap of 10 eV consistent with fourfold coordinated Ge and twofold coordinated O [REF]. The plasma-deposited GeO2 films are also qualitatively different than thin films prepared on Ge by thermal oxidation [REF], bulk glasses quenched at temperatures ¿850 C [8], and direct plasma deposited films in capacitive reactors [9]. These forms of GeO2 films (i) have very high concentrations of O-atom vacancies, (ii) are generally non-stoichiometric, and sometimes are sometimes diphasic. For example, the bulk glasses have a yellow color, and an absorption edge of 5.5 eV [8], and thermally grown GeO2 has a similar defect controlled absorption edge energy of 5.5 eV [6]. This is attributed to a decomposition reaction in which GeO is released from the GeO2 films, resulting in mid-gap GeGe bond formation [10]. This is labelled as GeOx in figure 3.4.
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