Physical Properties Of Films Research Articles

Effect of thickness and physical properties of films on the thermal behavior of a moving rough interface

Films are used in a wide range of electronic and mechanical technologies. An analytical solution is developed in this paper in order to investigate the effect of films on the thermal behavior at the vicinity of a static or moving rough interface. The roughness is modeled by multiple circular contacts which are assumed identical and regularly distributed over the interface according to a square net. The governing equations are solved by using the finite complex Fourier transform and the finite cosine Fourier transform. The developed solution is explicit and allows to calculate the three-dimensional steady-state temperature regardless of the velocity and the ratio of the real contact area to the apparent one. Thus, this solution can be also used for other applications such as the moving laser beam. The comparisons performed show a good agreement of our results with available models. We study the effects of: thermal properties of materials, the relative size of micro-contacts, the film thickness and the velocity, on the thermal behavior of the body.

Chemical Vapor Deposition of ZnS:Mn for Thin-Film Electroluminescent Display Applications

Results are presented from a systematic investigation to design and optimize a low-pressure chemical vapor deposition (CVD) process for manganese-doped zinc sulfide (ZnS:Mn) thin films for electroluminescent (EL) device applications. The CVD process used diethylzinc (DEZ), di-π-cyclopentadienyl manganese (CPMn), and hydrogen sulfide (H2S) as co-reactants and hydrogen (H2) as carrier gas. A design of experiments approach was used to derive functionality curves for the dependence of ZnS:Mn film properties on substrate temperature and flow rates (partial pressures) of DEZ, CPMn, H2S, and H2. Film physical, chemical, structural, and optical properties were examined using Rutherford backscattering spectrometry, dynamic secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, nuclear-reaction analysis, x-ray diffraction, transmission electron microscopy, atomic force microscopy, and scanning electron microscopy. EL measurements were carried out on ZnS:Mn-based dielectric–sulfur–dielectric stacks incorporated into alternating-current thin-film electroluminescent devices. An optimized process window was established for the formation of films with predominantly (0 0 2) orientation, grain size larger than 0.2 μm, and Mn dopant level approximately 0.5 at.%. A brightness of 407 cd/m2 (119 fL) and efficiency of 1.6 lm/W were obtained, as measured at 40 V above threshold voltage and 60 Hz frequency.

Thickness Uniformity of Double Bubble Tubular Film Process for Producing Biaxially Oriented PA 6 Film

Abstract It is known that while the double bubble tubular film process gives better impact strength and more uniform shrinkage balance than the tenter process, yet it is relatively poor in film thickness uniformity. The film thickness uniformity of the PA 6 produced by the double bubble tubular film process was investigated. The optimum stretching stress during the double bubble tubular film process exists. The bubble breaks over stress 130 MPa and bubble is unstable below stress 60 MPa. In the optimum condition, which is process temperature 310 °C and stretching ratio 3.2, stretched film uniformity was twice worse than non-stretched film one. The thickness uniformity of the film stretched in the optimum condition was better than that of the film stretched at higher process temperature and at lower stretching ratio. In the observations of the bubble sample through the polarizing plates, deformation pattern showed the equality of deformation. Thickness uniformity of non-stretched film significantly affects the thickness uniformity of biaxially oriented film. Local stretching ratio, which varies along the film width, influences tensile modulus and tensile strength at break. In order to obtain the uniform physical properties of film, it is important to produce the film with uniform thickness. Film thickness uniformity can be improved when stretching stress is high and bubble stability is good. These factors are influenced by stretching temperature, stretching ratio and air velocity from air ring.

Propriedades de filmes comestíveis produzidos com diferentes concentrações de plastificantes e de proteínas do músculo de tilápia-do-nilo

A utilização de proteínas sarcoplasmáticas junto de proteínas miofibrilares pode ser interessante na tecnologia de filmes comestíveis, pois eliminaria o processo de lavagem do músculo no preparo das proteínas. O objetivo deste trabalho foi estudar propriedades físicas de filmes constituídos de proteínas miofibrilares e sarcoplasmáticas do musculo de tilápia-do-nilo (Oreochromis niloticus), em razão da concentração de proteínas e do plastificante na solução filmogênica. Os filmes foram elaborados a partir de soluções filmogênicas contendo 1 e 2 g de proteínas do músculo/100 g de solução filmogênica e 15 a 65 g de glicerina/100 g de proteínas, com pH igual a 2,7 (ácido acético glacial), tratadas à temperatura de 90C por 30 minutos e desidratadas a 30° C por cerca de 24 horas. Os filmes produzidos com soluções de maior concentração de proteínas apresentaram-se mais coloridos, mais resistentes à perfuração e à tração, com maior capacidade de elongamento quando submetido à tração, e visivelmente mais opacos, embora nesse último caso, sem efeito significativo. As propriedades viscoelásticas e a deformação na perfuração não foram influenciadas pela concentração de proteínas. Todas as propriedades foram influenciadas pela concentração do plastificante.

Influence of substrate temperature on titanium oxynitride thin films prepared by reactive sputtering

Thin films of titanium oxynitride were successfully prepared by dc reactive magnetron sputtering using a titanium metallic target, argon, nitrogen and water vapour as reactive gases. The nitrogen partial pressure was kept constant during every deposition whereas that of the water vapour was systematically changed from 0 to 0.1 Pa. These films were made at room temperature (293 K) (set A) and at 673 K (set B). The study consisted in comparing the evolution of deposition parameters like target potential or deposition rate and physical properties of films for each set. Elemental composition measurements obtained by RBS and NRA revealed a reverse and continuous evolution of nitrogen and oxygen contents. Structure and morphology of the films were analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Films deposited at room temperature became amorphous with an increasing supply of water vapour. A higher substrate temperature led to significant changes of the crystallographic structure: from fcc TiN without water vapour to a mixture of anatase+rutile for large amount of water vapour. The optical transmittance spectra of the film/glass substrate system were measured in the visible region as a function of the water vapour pressure. For both sets A and B, optical transmittance was influenced by the water vapour partial pressure. Electrical conductivity measured against temperature was gradually modified from metallic ( σ 300 K =1.49×10 4 S m −1) to semi-conducting behaviour ( σ 300 K =2.15 S m −1) with an increasing supply of the water vapour partial pressure. Moreover, coatings prepared at room temperature exhibited a surprising maximum of the electrical conductivity for a small amount of water vapour (set A). Such surprising evolution vanished for set B with a restricted range of conductivity from σ 300 K =1.1×10 5 to 7×10 2 S m −1.

A single growth quality indicator for film property tailoring

A physical approach to approximation is proposed, representing a valuable aid for the analysis of complex-systems and physical processes and, generally, for the solution of problems involving a lot of variables. The deposition of hydrogenated carbon–nitride (a-CN:H) coatings by reactive-sputtering is here considered as an example for the method presentation. The existence of a clear reliance is demonstrated between growth-conditions and film physical properties, evidenced by Raman characterisation. The deposition parameters playing a relevant role in determining the final issue of the growth process are singled out and an empirical rule for tailoring the coatings characteristics, through specific changes of these variables, is therewith given. The generality of the proposed method is finally emphasised.

Flame assisted vapour deposition of cathode for solid oxide fuel cells. 1. Microstructure control from processing parameters

The flame assisted vapour deposition (FAVD) technique has been used to deposit porous lanthanum strontium manganese oxide (LSM) to produce the cathode for a solid oxide fuel cell (SOFC). FAVD combines flame synthesis and vapour deposition methods where the liquid precursor undergoes a combustion process into a vapour phase, and then deposits as an oxide film on a substrate. The work has shown that the microstructures of deposited films may be dense or porous depending on processing parameters such as the deposition temperature, the concentration of the fuel and the distance between the spray nozzle and the substrate. A mechanism for the effects of these processing parameters interpreted as ‘the combustion zone’ has been proposed. This mechanism is used to explain the physical properties of films which were characterised using SEM and XRD. The FAVD technique is shown to be an efficient way in which SOFCs’ cathode film can be fabricated with tailoring of the desired phases and microstructure.

The effect of In doping on some physical properties of CdS films

CdS and CdS:In films (at the In percentages of 25, 35 and 45) were deposited onto glass substrates at the substrate temperature of 300±5°C by ultrasonic spray pyrolysis technique and the effect of In concentration on some physical properties of the films were presented. The deposited films were characterized for their electrical, structural, morphological and elemental properties using current–voltage measurements, X-ray diffraction patterns, scanning electron microscopy micrographs and energy dispersive X-ray spectroscopy analyses, respectively. It was determined from the results of these investigations that the electrical, structural, morphological and elemental properties of CdS films considerably changed with In doping and CdS:In films are more desirable than CdS for window layer applications in photovoltaic solar cells.

HfO2 Gate Dielectrics Deposited via Tetrakis Diethylamido Hafnium

films deposited via tetrakis diethylamido hafnium (TDEAH) precursor using MOCVD (metal organic chemical vapor deposition) are presented. TDEAH is a promising precursor candidate for the deposition of high permittivity gate dielectrics. We report the impact of process and annealing conditions on the physical and electrical properties of the film. Deposition and annealing temperatures influence the microstructure, density, and impurity levels of TDEAH films. Spectroscopic ellipsometry shows that film microstructure manifests itself in the optical properties of the film, particularly in the presence of a band edge related feature at 5.8 eV. An impurity analysis using Auger electron spectroscopy, secondary ion mass spectroscopy, and Raman spectroscopy, indicates that carbon impurities from the precursor exist as clusters within the dielectric. The impact of deposition temperature and annealing temperature on the capacitance vs. voltage and current density vs. voltage characteristics of platinum gated capacitors is studied. Correlation of physical film properties with the capacitance and leakage behavior of the TDEAH films indicates that impurities, in the form of carbon clusters, and low film density are detrimental to the electrical performance of the gate dielectric. © 2003 The Electrochemical Society. All rights reserved.

Combined chemical–physical methods for enhancing IR photoconductive properties of PbS thin films

IR photoconductive properties of PbS films can be controlled using two different methods: (1) chemical, controlling the film morphology and, thus, the physical film properties by adding small amounts of impurities in the deposition bath, (2) physical, using field effect in complex PbS/SiO 2/Si pseudo-MOS structures to control the photoconductivity of PbS film.

Study of metal gate work function modulation using plasma and SiH4 treated TiN thin films

ABSTRACTAs gate oxide thickness decreases, the capacitance associated with the depleted layer in polysilicon gate becomes significant, making it necessary to consider alternative gate electrodes. Titanium nitride (TiN) films elaborated with TiCl4 precursor is widely studied as metal gate in semi-conductor technology. In this work, a study of TiN metal gate deposited by MOCVD using TDMAT (Tetrakisdimethylamino titanium) precursor is proposed. N2, H2 plasma application and SiH4 treatment after TiN thin film growth modify composition and microstructure. Consequently, they alter the physical properties of films. Such treatments may be a way to modulate work function and thus to control threshold voltage.Metallic layers were deposited in a chamber using a commercial 8 inch wafer deposition tool. In this study, structural and compositional properties of TiN were correlated with work function measurements. Firstly, the composition evolution (carbon content) was studied by AES and SIMS as a function of plasma and SiH4 treatments; XRD gave details on the microstructure. Secondly, MOS structures were processed on uniformly p-type doped wafers. C-V curves of capacitors were used to estimate the flat band voltage (VFB) and gave access to the work function, the effect of oxide fixed charges and the density of interface states. It is shown that as-deposited amorphous films exhibit a work function of 4.4 eV. Exposure to SiH4 is shown to increase this work function of about 150 meV. Thin films properties are not impacted by anneal treatments. Work function stability was tested at 425 °C, 900 °C and 1050 °C. Thermodynamic compatibility with gate oxide was verified thanks to experimental results and calculations.

Properties of carbon films and their biocompatibility using in-vitro tests

In this paper we report the results of a comparative study of the biological response of amorphous carbon coated stainless steel. Films of amorphous carbon (a-C), amorphous carbon nitride (a-CN) and hydrogenated amorphous carbon (a-C:H) were deposited on stainless steel substrates (AISI 316L) using a dc magnetron sputtering system. In-vitro studies were carried out on the coated samples using human osteoblasts cell culture lines and fibroblasts. Preliminary biocompatibility was assessed by cell adhesion and proliferation, as determined by a spectroscopic technique. Comparison of the optical absorbance results between control uncoated disks and the test cultures provided a semi-quantitative analysis of the cytotoxic effect of the different carbon compounds. Osteoblasts cells were grown on uncoated steel, a-C, a-CN and Ti coated steel samples. The degree of fibroblast adhesion measured at 24 h is very similar for all the test samples, however, osteoblasts adhesion was higher for a-C films. Similarly, cellular proliferation at 7 days showed an outstanding increase of osteoblasts cells for a-C and Ti in contrast with uncoated steel. The physical film properties, such as, roughness measured by atomic force microscopy, surface composition determined by both Rutherford Backscattering and Auger Spectroscopy and the electro-optic properties of the films were also determined. The relation between film properties and cellular response is discussed.

어육 단백질을 이용한 가식성 필름의 제조

어육 단백질로부터 가식성 필름을 제조하기 위하여 명태와 고등어로부터 최적 단백질 추출조건을 구명하고, 필름 제조용 용액의 단백질 농도, pH 및 온도가 필름의 물성에 미치는 영향을 조사하였다. 명태의 일반성분 함량은 수분 <TEX>$79.62\%$</TEX>, 조단백질 <TEX>$18.2\%$</TEX>, 조지방 <TEX>$0.6\%$</TEX>, 회분 <TEX>$1.3\%$</TEX>였으며, 고등어는 수분 <TEX>$69.1\%$</TEX>, 조단백질 <TEX>$20.1\%$</TEX>, 조지방 <TEX>$9.5\%$</TEX>, 회분 <TEX>$1.3\%$</TEX>로서 명태가 고등어에 비하여 수분함량은 높고 조단백질과 조지방 함량은 낮았다. 또한, 황함유 아미노산인 cysteine과 methionine 함량은 명태 771mg/100 g, 고등어 746mg/ 100 g 으로서 이들 아미노산의 비율은 그다지 높지 않았다 명태와 고등어로부터 가용성 단백질의 추출률은 pH 12에서 가장 높았으며. 다음으로 pH 2, 11의 순이었고, 중성부근에서는 추출률이 낮았다. 한편 추출된 가용성 단백질을 등전점 분리시켰을 때, 단백질의 회수율은 명태는 pH 4.8 (<TEX>$79.8\%$</TEX>)에서, 고등어는 pH 5.0 (<TEX>$64.1\%$</TEX>)에서 가장 높았다. 어육 단백질 필름은 증류수 100mL에 단백질 4g (glycerol 1.6g) 을 첨가하여 pH 10.0로 조정한 다음 <TEX>$90^{\circ}C$</TEX>로 가열하여 제조하는 것이 물리적 특성면에서 가장 우수하였다. To prepare the edible film based on fish protein, the optimal conditions for extracting soluble protein from Alaska pollack ( Theragra chalcogramma) and mackerel (Scomber japonious) muscle were defined. The effects of protein concentration, pH and temperature of protein solution on the physical properties of films were also investigated, Contents of moisture, crude protein, crude lipid and ash in Alaska pollack muscle were 79.6, 18.2, 0.6 and <TEX>$1.2\%$</TEX>, respectively. Contents of moisture, crude protein, crude lipid and ash in mackerel muscle were 69,1, 20.1, 9,5 and <TEX>$1.3\%$</TEX>, respectively. Both soluble protein contents extracted from Alaska pollack and mackerel were the highest at pH 12.0, and then un 2.0, 11.0. But they were extracted a little at neutral range. forward the recovery yield of protein by controlling isoelectric point was the highest at pH 4.8 (<TEX>$79.8\%$</TEX>) for Alaska pollack and at pH 5.0 (<TEX>$64.1\%$</TEX>) for mackerel, For the preparation of protein films from both Alaska pollack and mackerel, the most effective conditions of film forming solution were achieved, after supplied fish protein 4 g (glycerol 1,6 g) in 100 mL of distilled water, by adjusted to pH 10.0 and then heated at <TEX>$90^{\circ}C$</TEX>.

HDPE Barrier Film Resins - MW and MWD Effects - and their Blends with mLLPDE

High density polyethylene (HDPE) resins were produced via the multi-reactor, Mitsui, stirred slurry process to give a `four corners' type of product matrix with high and low molecular weights (MW) and broad and narrow molecular weight distributions (MWDs). Density was kept constant. Film processing and physical properties - including oxygen, carbon dioxide, and water vapor transmission rates - are presented. Lower MW and narrower MWD favor better barrier properties. The best barrier HDPE resin was blended with mLLDPE and films blown from these blends demonstrated the potential for application specific film strength and optical property tailoring while maintaining high barrier performance.

Characterization of RF-sputtered self-polarized PZT thin films for IR sensor arrays

In this work, a complex investigation of film composition, microstructure and physical properties of RF-sputtered self-polarized PZT thin films for IR sensor arrays was carried out. Hydrostatic stresses in Si substrates near edges of Pt/PZT microstructures were predicted theoretically by finite element calculations and measured by spatially resolved Raman spectroscopy. High hydrostatic stresses were obtained in patterned sensor pixels by Raman piezo-spectroscopy. The laser-intensity-modulation method was applied for the investigation of the self-polarization profile, whereas the depth profile of the refractive index was determined by means of spectroscopic ellipsometry. Polarization and refractive index profiles as well as interface stresses affect IR-radiation sensor performance. Thickness and area dependences of IR-radiation detector detectivity and noise equivalent temperature difference were calculated. The applications of self-polarized IR sensor arrays in presence detection and IR imaging are demonstrated.

Physical Properties of WPI Films Plasticized with Glycerol, Xylitol, or Sorbitol

ABSTRACT: Effects of glycerol, xylitol, and sorbitol on selected physical properties of whey protein isolate (WPI) films were examined. Increasing glycerol or sorbitol content led to increases in moisture content, water vapor permeability, and % elongation; and decreases in tensile strength, elastic modulus, and glass transition temperatures of the films. Increasing levels of xylitol had no effect on permeability, moisture content, or glass transition temperature of the films, but decreased % elongation, tensile strength, and elastic modulus. Moisture content of the films correlated well with glass transition temperatures. Differences in measured physical properties of films with plasticizer type and concentration may be attributed to differences in the hygroscopic and crystalline properties of the plasticizers.

Study on physical properties of blend films from gelatin and polyacrylamide solutions

AbstractBlend films of gelatin and polyacrylamide (PAAm) were prepared by casting the mixed aqueous solutions of both samples in different ratios. All blend films obtained are optically clear to the naked eye. The structure and physical properties of the films were studied by FT‐infrared (FTIR), wide‐angle X‐ray diffraction (WAXD), differential thermal analysis (DTA), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The experimental results show that the blend films exhibit the higher thermal stability and improved mechanical properties of both tensile strength and elongation at break in dry states, which suggests the occurrence of interaction detected by FTIR between gelatin, PAAm, and water molecules in the films. The morphological transition of the blend films from gelatin‐like to PAAm‐like was observed by SEM. Furthermore, moisture content and water swelling property of the blend films were also investigated, which was consistent with the results from SEM. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 949–955, 2002

Electroless-deposited Ag–W films for microelectronics applications

Thin Ag–W films, with a tungsten concentration of up to 3.2 at.% and a thickness in the range 20–300 nm, were directly deposited on Si(100) substrate by the electroless (auto-catalytic) method. The deposition characteristics and the thin film electrical and physical properties were studied as a function of the bath composition. The role of tungsten in the silver matrix was studied via measurements of the film microhardness and thermal stability as a function of the thin film composition. Ag–W films thicker than 200 nm had a shiny appearance with good reflectivity and their specific electrical resistivity was 2 μΩ cm. The specific resistivity of films increased with decreasing thickness. Exposure of electroless silver films to air at 200°C for a few h causes them to tarnish severely and their sheet resistance to significantly increase, while similar Ag–W films were not affected under the same conditions. Therefore, we assume that silver–tungsten films can be used for applications that require reliable conducting thin films, such as packaging and interconnects for microelectronics.

Nature of non-D and non-G bands in Raman spectra of a-C:H(N) films grown by reactive sputtering

The Raman spectra of sputter-grown a-C:H(N) films are analyzed giving particular emphasis to the regions below and above that dominated by the well-known D and G bands, in order to deduce complementary information about the film physical properties and eventually clarify the nature of the features there detected. The conventionally studied evolution of the D and G bands evidences a sharp tendency toward graphitization, accompanied by an increasing level of structural disorder. The weak feature observed at about 700 cm−1 is assigned to the disorder-induced L band, originating from the formation, within the films, of graphitic microcrystallites, whose number and size are shown to change when the partial pressure of argon is varied. Thanks to the complementary infrared film characterization, indicating no appreciable hydrogen incorporation into the investigated samples, the broad asymmetrical Raman band centered at about 3000 cm−1 is suggested to represent the second order of the D and G bands, whose component detection and broadening are likely to represent a finite-crystal-size effect, due to the very small size of graphitic crystallites. A semiquantitative explanation of the observed dependence of the second- on the first-order integrated intensity is given.

Preparation and characterization of konjac glucomannan and sodium carboxymethylcellulose blend films

The novel blend films of konjac glucomannan (KGM) and sodium carboxymethylcellulose (NaCMC) were prepared by casting the mixed polymer aqueous solutions. The physical properties of the blend films from konjac glucomannan and sodium carboxymethylcellulose were investigated by using FT-infrared (FTIR), wide-angle X-ray diffraction (WAXD), differential thermal analysis (DTA), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and measurements of mechanical properties. The experimental results showed that the occurrence of the interactions between KGM and NaCMC molecular chains through hydrogen bond formation, and the physical properties of the films largely depend on the blending ratio. The thermal stability, mechanical properties of both tensile strength, and elongation at break of the blend films were improved by blending KGM with NaCMC. The surface morphology of the films observed by SEM was consistent with the results mentioned above.