bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silicon Surface Micromachined Structures for the Stress Measurement of Thin Films
Authors: Mutikainen Risto , Orpana Markku 
Published: March 2011

ABSTRACTThe realization of structures with silicon surface micromachining requires very low stresses of the structural elements. When low tensile film strains have been difficult to measure as no double-beam type structures susceptible for buckling at low tensile strains have been in use, a new “diamond beam” structure is proposed for the tensile-to-compressive strain conversion. The device performance is analysed as a strain gauge.The micromachined structures can also be used as substrates for deposited films. The formulation is presented for double beam as substrate for deposited film compressive strain gauging. The structures were applied for strained sputter-deposited Molybdenum, and it was found that large undercut of the double beam edge must be avoided as well as the spacer film thickness must be large enough for beam buckling to be noticeable.
Accuracy and Reliability of Bulge Test Experiments
Authors: Small Martha K. , Vlassak Joost J. , Powell Stephen F. , Daniels Brian J. , Nix William D. 
Published: March 2011

ABSTRACTIn this paper we address possible causes for inconsistencies in bulge test results and describe methods by which the bulge test technique can be made to produce accurate and reliable results. Experiments have been conducted on a variety of materials: polyimide (PIQ13) and polycarbonate (Lexan), silver and silver-palladium multilayers, and silicon nitride. All the materials tested yield biaxial moduli that are in the range of expected values for the bulk material. In addition, the tests show that the technique can be used to differentiate between the elastic properties of materials throughout the range of elastic stiffnesses, with even crystallo-graphic texture having a notable impact on the measured modulus. These results will be presented along with the methods used for preparing bulge test samples.
Modeling of the Blister Test to Express Adhesive Strength in Terms of Measurable Quantities
Authors: Sizemore Jim , Stevenson David A. , Stringer John 
Published: March 2011

ABSTRACTThe adhesion of chemical vapor deposited (CVD) diamond thin films to substrates is a major limitation to using this new and exciting material. It is important to have a quantitative and absolute measurement of adhesive strength to understand and identify remedies. There are many methods to measure adhesion, but most rely on comparison to a standard instead of being an absolute measurement. The blister test is potentially able to measure adhesion both quantitatively and absolutely, but the existing analysis is not sufficient. This paper presents a fracture mechanics approach to analyze the blister test for a circular plate in order to obtain the appropriate quantitative information, i.e., the crack extension force,G. Several shape models exist. We consider several models to predict the behavior of this plate and then derive an equation that expressesGin terms of the critical pressure and critical volume at which de-bonding occurs. As a result of this analysis, we identify the key experimental parameters and show that this equation is insensitive to the model used.
A Simple Method for Determination of the Elastic Modulus of Thin Films on a Substrate
Authors: Swain M.V. , Weppelmann E.R. 
Published: March 2011

ABSTRACTHigh precision force displacement indenting instruments are now widely used for the determination of the mechanical properties of materials. However, for thin films attached to a substrate, the basis of any analysis of such high precision data is still limited. In this study the force displacement data has been generated using spherically tipped indenters of radii from 5 to 150 μm loaded onto a 2.74 μm thick TiN film on a silicon substrate as well as onto the substrate directly. Data have been generated using two loading procedures, continuous and load partial-unloading, almost entirely within the elastic contact regime. The results are analysed to determine the modulus of the TiN film.
Effect of the Substrate on Microindentation Behavior
Authors: Lardner T.J. , Ritter J.E. , Karamustafa H.B. 
Published: March 2011

ABSTRACTA continuous microindentation apparatus was constructed with a maximum load capacity of 45 N (resolution of 0.1 N) and with a maximum displacement of 500 μm (resolution of 2.0 μm) and used to test bulk materials (brass, aluminum, steel, soda-lime glass and PMMA) and epoxy coatings on substrates of aluminum, steel, soda-lime glass and PMMA. The hardness (H) was determined with a Vickers indenter and compared to that obtained with a Tukon hardness tester. The elastic modulus of the coated systems was also estimated from the unloading curves. In general, we found that the indentation behavior of the epoxy coated system was influenced by the substrate with softer substrates (as with PMMA) being deformed before the indenter penetrates the coating. With all coated systems, the on-load value of H was independent of the penetration depth until the indenter penetrated the substrate. For the aluminum, steel and soda-lime glass substrates, the value of H after penetration increased slowly due to the pile up of the epoxy coating underneath the indenter supporting more of the load. For the PMMA substrate, hardness decreased after penetration because the hardness of PMMA was less than the epoxy coating.
Real Time Stress Measurements During Growth of Aluminum Nitride on SI(111) and SI(001)
Authors: Meng W. J. , Sell J. A. , Eesley G. L. , Perry T. A. 
Published: March 2011

ABSTRACTWe have performed real time measurements of intrinsic stresses during growth by reactive dc magnetron sputtering of aluminum nitride (AlN) thin films on silicon substrates in an UHV growth chamber. An experimental setup based on laser beam reflection is constructed such that substrate curvature as well as film thickness can be continuously monitored as growth proceeds. On Si(111) substrates, stress measurements were carried out during growth of both polycrystalline and epitaxial A1N films as a function of deposition pressure. This is the first such comparative study to our knowledge for the AlN/Si system. Our room temperature measurements on polycrystalline films corroborates previous post-growth measurements. Our high temperature measurements provide evidence of large intrinsic stresses and negligible stress relaxation during epitaxial growth of AlN on Si(111). We further compared stress behavior during both room temperature and high temperature growth of AlN films on Si(111) and Si(001) substrates. Our observations indicate while intrinsic stresses during room temperature growth can be compressive or tensile depending on plasma conditions, it is tensile during late stage growth at high temperatures.
Micro-Wear Technique and its Application to Ultra Thin Film Systems
Authors: Wu T.W. , Lee C.-K. 
Published: March 2011

ABSTRACTA micro-wear testing technique has been developed by incorporating a piezoelectric pusher into an existing micro-indenter system. The pusher and its associated servo-control circuitry were designed to generate a precise reciprocating horizontal motion at the indenter tip for implementing micro-scaled wear test. The information acquired from the test includes the wear loading curve, i.e., the normal applied load versus wear penetration depth, the friction force and in turn, the apparent wear friction coefficient. Acquiring the electrical resistance across the coating thickness is also possible if an electrical conducting indenter is utilized. Furthermore, in collaboration with the surface characterization tools, the wear morphology revealed useful information regarding the coating failure mechanism(s) and shed some light towards understanding coating tribology. The tester design concepts, operating procedure, data acquisition and analysis will be examined. Experimental results on ultra thin carbon coatings with various thicknesses will be employed to illustrate the capabilities of the microwear tester.
Validity of Adhesion between Films and Substrate with Friction-Detected Scratch Test
Authors: Wang Ru 
Published: March 2011

ABSTRACTThe validity of Lc of film failure is studied with friction — detected scratch test . The specimens used in the experiment are ion-plated TiN and Ti films,Chemical-Plated NiPCu films on steel of various hardness,ion beam mixed plated TiN films on optical glass,The morphology of failed films was studied under optical microscope and scanning electronmicroscope,The composition of starting failure of films was analyzed with electro — probe. It is found that in the curves of scratch tests of ion-plated TiN and Ti films on high-speed steel,the load corresponding the sudden change of the horizontal force is the same as the critical load of film failure,however,the critical load obtained in the scratch test of the ion-plated TiN and Ti films on soft steel is the some deference compared with optical microscope analyzed, that is principally due to the property of films and substrates (hardness and coefficient).The morphology and mechanism of ion — plated TiN and Ti films on high —speed steel are also studied in the paper.The adhesion between film and substrate is an effective method in evaluating the films property. After apprasing the effectiveness of acoustic emission monitoring scratch test, someone think that no matter coated with hard or soft film it is effective on the brittle hard substrate. However,there exist errors to different extent on other film-substrate system,and the scratch test is inapplicable for soft film-soft substrate system[1]. P. A. Steinmann pointed out while studying the factors influnceing the critical load Lc,that friction coefficient is a key factor on Lc,it provided valuable information in measuring Lc,but it think it is imporsible to measure Lc totally dependent on sudden change friction or friction coefficient, howeveer, for a specific coating substrate system,it is acceptable to say that Lc is dependent on friction coefficient[2]. This paper study experimentally on the friction detected scratch test and found out that effectiveness of Lc varies substantially in different film-substrate system. The author studiied the regularity of various system and discuse the season. The failure morphology and principles of ion-plated TiN and Ti film on highspeed steel are also analyzed in this paper.
Strain Relaxation and In-Situ Observation of Voiding in Passivated Aluminum Alloy Lines.
Authors: Besser Paul R. , Marieb Thomas N. , Bravman John C. 
Published: March 2011

ABSTRACTStrain relaxation in passivated Al-0.5% Cu lines was measured using X-ray diffraction coupled with in-situ observation of the formation and growth of stress induced voids. Samples of 1 μm thick Al-0.5% Cu lines passivated with Si3N4 were heated to 380ºC, then cooled and held at 150ºC. During the test, principal strains along the length, width, and height of the line were determined using a grazing incidence x-ray geometry. From these measurements the hydrostatic strain in the metal was calculated and strain relaxation was observed. The thermal cycle was duplicated in a high voltage scanning transmission electron microscope equipped with a backscattered electron detector. The 1.25 μm wide lines were seen to have initial stress voids. Upon heating these voids reduced in size until no longer observable. Once the samples were cooled to 150ºC, voids reappeared and grew. The measured strain relaxation is discussed in terms of void and θ-phase (Al2Cu) formation.
Analysis of Stresses at Singular Points of Patterned Structures.
Authors: Chouaf A. , Loppin G. , Ignat M. , Terriez J.M. 
Published: March 2011

ABSTRACTAn iterative method describing the stress state at the vicinity of singularity point is presented here. This approach is based on concepts of rupture mechanics, uses classical solutions from finite element calculations and concerns plane problems. Through this approach, the stress state at the vicinity of several types of singular points in a patterned structure were analysed. The obtained results can be discussed according to failure mecanisms.
Analysis of Thermal Stress Induced Void Growth During Thermal Cycling
Authors: Brown D.D. , Korhonen M.A. , Børgesen P. , Li C.-Y. 
Published: March 2011

ABSTRACTRecent work in thermal stress induced voiding in passivated lines has focussed on the isothermal, quasi-steady state growth of existing voids. In this work, the transient growth and shrinkage of voids during the thermal cycling of narrow, passivated lines was studied. Analysis of experimental data for passivated lines demonstrates the quick buildup and evolution of a backstress at the grain boundary during heating and cooling. This backstress greatly reduces the driving force for void growth at higher temperatures and must be accounted for in stress induced void growth models for the case of appreciably varying temperatures in short time scales.
Determination of the Mechanical Response of Thin Films with X-Rays
Authors: Noyan I. C. , Sheikh G. 
Published: March 2011

ABSTRACTThe mechanical response of a specimen incorporating thin films is dictated by a combination of fundamental mechanical parameters such as Young's moduli of the individual layers, and by configurational parameters such as adhesion strength at the interface(s), residual stress distribution and other process dependent factors. In most systems, the overall response will be dominated by the properties of the (much thicker) substrate. Failure within the individual layers, on the other hand, is dependent on the local strain distributions and can not be predicted from the substrate values alone. To better understand the mechanical response of these systems, the strain within the individual layers of the thin film system must be measured and correlated with applied stresses. Phase selectivity of X-ray stress/strain analysis techniques is well suited for this purpose. In this paper, we will review the use of the traditional x-ray stress/strain analysis methods for the determination of the mechanical properties of thin film systems.
Grain Boundary Sliding in Thin Substrate-Bonded AL Films
Authors: Prieler M. , Bohn H.G. , Schilling W. , Trinkaus H. 
Published: March 2011

ABSTRACTA systematic investigation of the anelastic relaxation of thin Al films on Si substrates has been carried out. It was found that both the relaxation in bulk and thin film material can be explained by a model involving glide of grain boundaries (GBs). The mass transport necessary for the glide occurs via GB diffusion in the thin films and via lattice diffusion in the bulk material the different behavior being due to the more of two orders of magnitude smaller grains in the films. Internal friction thus provides a technique to measure diffusional parameters of GB diffusion in thin films.
Effects of Confinement on Plastic Deformation in Passivated AL Films
Authors: Anderson S.G.H. , Yeo I.-S. , Ho P.S. , Ramaswami S. , Cheung R. 
Published: March 2011

ABSTRACTWafer curvature measurements of a trilayer (SiO2 / AlSiCu / Si) structure are compared to that predicted by a weighted sum of individual measurements of SiO2 and AlSiCu films on Si, and significant differences are found to exist for temperatures above 200°C. A straightforward analysis of the stresses in each layer has been modeled using an extension of a model by Feng et al. which assumes uniform plastic deformation throughout the Al. The modeling results suggest a straightforeward method for determining stresses in deformable thin films that are confined by elastic overlayers. A comparison of the stress-temperature behavior for unpassivated and passivated AlSiCu films reveals that the confined films exhibit less plastic deformation and both higher tension and compression during thermal cycling.
Variation of Local Mechanical Stress During the Different Processing Steps of Ic-Isolation: a Micro-Raman Spectroscopy Study
Authors: De Wolf Ingrid , Maes Herman E. , Norström Hans 
Published: March 2011

ABSTRACTLocal mechanical stress introduced in the silicon substrate during the successive steps of poly-buffered local isolation of MOS integrated circuits is studied with micro-Raman spectroscopy. It is shown that the magnitude and the local variation of the stress is highly affected by the different processing steps. After deposition of the nitride mask, the stress can be described as caused by an edge-force. Field oxidation reduces the mask-induced stress but introduces thermal stress from the field oxide. Also the formation of the bird's beak gives rise to additional local tensile stress, especially at the tip of the bird's beak. Removal of the nitride mask results in a partial relaxation: the stress caused by the bird's beak relaxes. In this last stage of the isolation process, the stress image is mostly determined by the field oxide.
Mechanical Stress Measurements in Window-Plated Permalloy Thin Film Strips
Authors: Ross C. A. 
Published: March 2011

ABSTRACTMechanical stress measurements in long window-plated strips of permalloy have been made and show an anisotropy in the in-plane stresses. The stress parallel to the strip length is independent of the strip width and thickness, and exceeds the in-plane stress perpendicular to the strip length. The difference between the two stresses depends on the ratio of strip width to thickness, and is in agreement with finite element simulations of stress distributions in similar thin film strips which are etched out of a sheet film of the same material. This result allows calculations of intrinsic stress distributions in more complex window-plated structures. The effect of annealing on the strips is to increase the in-plane stress anisotropy as well as the overall level of stress, by an amount which increases with the annealing temperature.
Growth of Strain-Free GaAs on Si/Sapphire
Authors: Sohn Hyunchul , Weber E.R. , Tu Jay , Smith J.S. 
Published: March 2011

ABSTRACTGaAs epitaxial layers were successfully grown on Si/Sapphire substrates using Molecular Beam Epitaxy(MBE). Residual compressive strain was found in GaAs films on Si/Sapphire. By Photoluminescence, the magnitude of residual strain in GaAs on Si/Sapphire was estimated to be 5×10-4 which is about one order smaller than that of GaAs on Si.As an effort to achieve further reduction in the residual strain, Indium- doped GaAs films were used as buffer layers in order to compensate compressive thermal strain by tensile misfit strain in the GaAs layer. Using this method, strain- free GaAs layers could be grown with thickness up to 0.4 μm on Si/Sapphire.
Barriers to Strain Relaxation in Epitaxial Fluorides on Si(111)
Authors: Li Weidan , Hymes Steve , Murarka Shyam P. , Schowalter Leo J. 
Published: March 2011

ABSTRACTThe mechanical stress of epitaxial SrF2 and CaF2 films on Si(111) substrates has been measured as a function of temperature by the substrate curvature technique. The temperature dependence of the stress in the SrF2 film is interpreted in terms of an energy barrier to dislocation motion. When the strain energy is smaller than the value needed to overcome the barrier, the change in stress is due mainly to elastic deformation. As the temperature change increases, the strain energy becomes large enough to overcome the barrier, at which point plastic deformation initiates. Unlike SrF2, the stress behavior of the CaF2 film for increasing temperature is quite different from its behavior for decreasing temperature. This unusual behavior is not understood at this time.
Electronic structure of short-period ZnSe/ZnTe superlattices grown by MOVPE at 300ºC
Authors: Briot N. , Cloitre T. , Briot O. , Boring P. , Ponga B.E. , Gil B. , Aulombard R.L. , Gailhanou M. , Sallese J.M. , Jones A.C. 
Published: March 2011

ABSTRACTThe ZnSe-ZnTe combination is a potential candidate for the realisation of visible light-emitting devices. The lattice mismatch between bulk ZnSe and bulk ZnTe is important (∼ 8%). Therefore, their hetero-structures are strained and high quality superlattices will only be grown if having small periods. This prescription can be fulfilled in the case of metal organic vapour phase epitaxy (MOVPE) growth by combining triethylamine dimethyl zinc adduct with di-isopropyl telluride as precursors for the growth of the ZnTe layers. The growth of high quality ZnTe can then be performed at a temperature of 300ºC , close to the best MOVPE-growth temperature for ZnSe (280ºC). Lowering the growth temperature of ZnTe to this value, we could thus obtain sharp interfaces. This work reports on ZnSe-ZnTe superlattices grown on ZnSe and ZnTe buffers deposited on GaAs substrates. We demonstrate that the stokes-shift between the reflectance and photoluminescence features ( ∼ 40 meV ) measured when the thickness of ZnSe layers does not exceed 20 Å, drastically increases for layer thicknesses beyond this critical value. This, we interpret in terms of the onset of plastic relaxation which favours tellurium diffusion in the ZnSe slices. Then photoluminescence spectra broaden ( contributions of trapped-excitons dominate), and observation of free excitons in reflectance become impossible. We have studied in detail the optical properties of the superlattices and compared our findings with the predictions of a multiband envelope function calculation. We show that both zone centre excitons as well as excitons associated with the miniband dispersions (saddle-point excitons) are observed in these superlattices.
Stability of the Fullerenes Thin Film Deposited on the SI(100) Surface
Authors: Rafii-Tabar H. , Kawazoe Y. , Kamiyama H. 
Published: March 2011

ABSTRACTWe have performed a constant temperature classical molecular dynamics simulation of the epitaxial growth of a C60 monolayer film deposited on the dimerized Si(100) surface. Our simulation, based on non-central many-body inter-atomic potentials, is capable of predicting the structural stability of the C60 film and the Si substrate and provides a theoretical basis for the results of a recently-performed STM- based experiment for this system.Three-dimensional geometries have been generated on computer and used for the animation of the simulation runs.
Planarization with Cyclotene™ 3022 (BCB) Polymer Coatings
Authors: Stokich T.M. , Fulks C.C. , Bernius M.T. , Burdeaux D.C. , Garrou P.E. , Heistand R.H. 
Published: March 2011

ABSTRACTThis work examines the planarization of polymer thin film coatings derived from Cyclotene™ 3022 prepolymer resins. Cyclotene™ 3022 is a divinyl siloxane bis-benzocyclobutene prepolymer (DVS-BCB, CAS 117732-87-3). It is used primarily as a dielectric in microelectronics applications.Using profilometry, planarization measurements have been made on thin films spun over features consisting of lines and trenches. Feature widths have been varied from 2 to 1000 μm and the feature depths and film thickness have been varied from 1 to 16 μm. Effects of the processing procedure, resin concentration and resin additives have been explored. Local (versus global) planarization will be discussed.Planarization has been found to depend on all feature dimensions and the polymer film thickness. Lines or other structures having a width of 100 μm or less can be planarized to 90% or better with standard commercial formulations of Cyclotene™ 3022, provided that the mean film thickness is twice the line-height or feature-depth. Metals such as Al, Cu, Cr and Ti can all be planarized to this degree; however, surface preparations may influence the result.