Cracking Mechanisms of Fine Lines by Microwedge Scratch Testing

1994 ◽  
Vol 338 ◽  
Author(s):  
M. P. dE Boer ◽  
H. Huang ◽  
J. C. Nelson ◽  
E. T. Lilleodden ◽  
W. W. Gerberich

ABSTRACTThree types of cracks associated with interfacial failure of a tungsten fine line on silicon oxide (SiO2) have been observed in microwedge scratch testing (MWST) of fine lines. They were identified by carefully controlling scratch conditions in a continuous microindenter system1, in conjunction with SEM micrographs. The first type is a hinge crack, which is responsible for nucleating an interfacial crack. The driving force for the hinge crack is the difference in stress conditions in the middle on theline (plane strain) and the outside of the line (plane stress). The second type is the interfacial crack, which is driven by the movement of the microwedge. This crack is modelled by the finite element method (FEM) to obtain an interfacial work of adhesion value. The third type of crack is a spallation crack, and is driven by tensile strains associated with buckling of the thin film once the interfacial crack becomes sufficiently long. Tensile strains in the film at the maximum crack length are calculated by FEM in order to arrive at a value of thin film fracture strength. A brittle failure mechanism has beenconfirmed by a micrograph of a spalled piece exhibiting no perceptible plastic deformation.

Author(s):  
Wentao Qin ◽  
Dorai Iyer ◽  
Jim Morgan ◽  
Carroll Casteel ◽  
Robert Watkins ◽  
...  

Abstract Ni(5 at.%Pt ) films were silicided at a temperature below 400 °C and at 550 °C. The two silicidation temperatures had produced different responses to the subsequent metal etch. Catastrophic removal of the silicide was seen with the low silicidation temperature, while the desired etch selectivity was achieved with the high silicidation temperature. The surface microstructures developed were characterized with TEM and Auger depth profiling. The data correlate with both silicidation temperatures and ultimately the difference in the response to the metal etch. With the high silicidation temperature, there existed a thin Si-oxide film that was close to the surface and embedded with particles which contain metals. This thin film is expected to contribute significantly to the desired etch selectivity. The formation of this layer is interpreted thermodynamically.


2021 ◽  
Vol 13 (12) ◽  
pp. 6914
Author(s):  
Frikkie Alberts Maré ◽  
Henry Jordaan

The high water intake and wastewater discharge of slaughterhouses have been a concern for many years. One neglected factor in previous research is allocating the water footprint (WF) to beef production’s different products and by-products. The objective of this article was to estimate the WF of different cattle breeds at a slaughterhouse and cutting plant and allocate it according to the different cuts (products) and by-products of beef based on the value fraction of each. The results indicated a negative relationship between the carcass weight and the processing WF when the different breeds were compared. Regarding a specific cut of beef, a kilogram of rib eye from the heaviest breed had a processing WF of 614.57 L/kg, compared to the 919.91 L/kg for the rib eye of the lightest breed. A comparison of the different cuts indicated that high-value cuts had higher WFs than low-value cuts. The difference between a kilogram of rib eye and flank was 426.26 L/kg for the heaviest breed and 637.86 L/kg for the lightest breed. An option to reduce the processing WF of beef is to lessen the WF by slaughtering heavier animals. This will require no extra investment from the slaughterhouse. At the same time, the returns should increase as the average production inputs per kilogram of output (carcass) should reduce, as the slaughterhouse will process more kilograms.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4056
Author(s):  
José Javier Imas ◽  
Carlos R. Zamarreño ◽  
Ignacio del Villar ◽  
Ignacio R. Matías

A fiber Bragg grating patterned on a SnO2 thin film deposited on the flat surface of a D-shaped polished optical fiber is studied in this work. The fabrication parameters of this structure were optimized to achieve a trade-off among reflected power, full width half maximum (FWHM), sensitivity to the surrounding refractive index (SRI), and figure of merit (FOM). In the first place, the influence of the thin film thickness, the cladding thickness between the core and the flat surface of the D-shaped fiber (neck), and the length of the D-shaped zone over the reflected power and the FWHM were assessed. Reflected peak powers in the range from −2 dB to −10 dB can be easily achieved with FWHM below 100 pm. In the second place, the sensitivity to the SRI, the FWHM, and the FOM were analyzed for variations of the SRI in the 1.33–1.4 range, the neck, and the thin-film thickness. The best sensitivities theoretically achieved for this device are next to 40 nm/RIU, while the best FOM has a value of 114 RIU−1.


2005 ◽  
Vol 297-300 ◽  
pp. 1446-1451 ◽  
Author(s):  
Takeshi Kasuya ◽  
Hideto Suzuki

The fatigue strength of TiAl intermetallic alloy coated with TiAlN film was studied in vacuum at 1073K using a SEM-servo testing machine. In addition, three kinds of TiAlN films were given by physical vapor deposition (1, 3, and 10μ m). The fatigue strength of 3μ m was highest. Also, the fatigue strength of 1μ m was lowest. From this result, existence of optimum film thickness was suggested because the difference of fatigue strength arose in each film thickness. The justification for existence of optimum film thickness is competition of 45-degree crack and 90-degree crack. The 45-degree crack is phenomenon seen in the thin film (1μ m), and is caused by plastic deformation of TiAl substrate. The 45-degree crack is the factor of the fatigue strength fall by the side of thin film. In contrast, the 90-degree crack is phenomenon in the thick film (10μ m), and is caused as result of reaction against load to film. The 90-degree crack is the factor of the fatigue strength fall by the side of thick film. In conclusion, the optimum film thickness can perform meso fracture control, and improves fatigue strength.


2011 ◽  
Vol 1287 ◽  
Author(s):  
Anupama Mallikarjunan ◽  
Laura M Matz ◽  
Andrew D Johnson ◽  
Raymond N Vrtis ◽  
Manchao Xiao ◽  
...  

ABSTRACTThe electrical and physical quality of gate and passivation dielectrics significantly impacts the device performance of thin film transistors (TFTs). The passivation dielectric also needs to act as a barrier to protect the TFT device. As low temperature TFT processing becomes a requirement for novel applications and plastic substrates, there is a need for materials innovation that enables high quality plasma enhanced chemical vapor deposition (PECVD) gate dielectric deposition. In this context, this paper discusses structure-property relationships and strategies for precursor development in silicon nitride, silicon oxycarbide (SiOC) and silicon oxide films. Experiments with passivation SiOC films demonstrate the benefit of a superior precursor (LkB-500) and standard process optimization to enable lower temperature depositions. For gate SiO2 deposition (that are used with polysilicon TFTs for example), organosilicon precursors containing different types and amounts of Si, C, O and H bonding were experimentally compared to the industry standard TEOS (tetraethoxysilane) at different process conditions and temperatures. Major differences were identified in film quality especially wet etch rate or WER (correlating to film density) and dielectric constant (k) values (correlating to moisture absorption). Gate quality SiO2 films can be deposited by choosing precursors that can minimize residual Si-OH groups and enable higher density stable moisture-free films. For e.g., the optimized precursor AP-LTO® 770 is clearly better than TEOS for low temperature PECVD depositions based on density, WER, k charge density (measured by flatband voltage or Vfb); and leakage and breakdown voltage (Vbd) measurements. The design and development of such novel precursors is a key factor to successfully enable manufacturing of advanced low temperature processed devices.


2000 ◽  
Vol 657 ◽  
Author(s):  
Youngman Kim ◽  
Sung-Ho Choo

ABSTRACTThe mechanical properties of thin film materials are known to be different from those of bulk materials, which are generally overlooked in practice. The difference in mechanical properties can be misleading in the estimation of residual stress states in micro-gas sensors with multi-layer structures during manufacturing and in service.In this study the residual stress of each film layer in a micro-gas sensor was measured according to the five difference sets of film stacking structure used for the sensor. The Pt thin film layer was found to have the highest tensile residual stress, which may affect the reliability of the micro-gas sensor. For the Pt layer the changes in residual stress were measured as a function of processing variables and thermal cycling.


1966 ◽  
Vol 21 (9) ◽  
pp. 1377-1384
Author(s):  
A. V. Willi

Kinetic carbon-13 and deuterium isotope effects are calculated for the SN2 reaction of CH3I with CN-. The normal vibrational frequencies of CH3I, the transition state I · · · CH3 · · · CN, and the corresponding isotope substituted reactants and transition states are evaluated from the force constants by solving the secular equation on an IBM 7094 computer.Values for 7 force constants of the planar CH3 moiety in the transition state (with an sp2 C atom) are obtained by comparison with suitable stable molecules. The stretching force constants related to the bonds being broken or newly formed (fCC, fCC and the interaction between these two stretches, /12) are chosen in such a way that either a zero or imaginary value for νʟ≠ will result. Agreement between calculated and experimental methyl-C13 isotope effects (k12/ k13) can be obtained only in sample calculations with sufficiently large values of f12 which lead to imaginary νʟ≠ values. Furthermore, the difference between fCI and fCC must be small (in the order of 1 mdyn/Å). The bending force constants, fHCI and fHCC, exert relatively little influence on k12/k13. They are important for the D isotope effect, however. As soon as experimental data on kH/kD are available it will be possible to derive a value for fHCC in the transition state if fHCI is kept constant at 0.205 mdynA, and if fCI, fCC and f12 are held in a reasonable order of magnitude. There is no agreement between experimental and calculated cyanide-C13 isotope effects. Possible explanations are discussed. — Since fCI and fCC cannot differ much it must be concluded that the transition state is relatively “symmetric”, with approximately equal amounts of bond making and bond breaking.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Farah Aida Qotrun Nada ◽  
Tintrim Rahayu ◽  
Ari Hayati

Ground coffee is coffee beans that have been roasted, ground or ground so that they have a smooth shape. The purpose of this study was to determine the content of compounds in robusta coffee roasted seed extract (Coffea canephora) from plants produced by organic and inorganic fertilization, and to know the difference in compounds between the results of organic and inorganic fertilization. The characteristics of phytochemical screening were carried out qualitatively on alkaloids, flavonoids, tannins, terpenoids and saponins and the antioxidant activity was carried out by the DPPH (1,1-dipenyl-2-picrihidrazil) method. Phytochemical screening characteristic test results show that robusta coffee bean extract extract from the results of organic and inorganic fertilization both contain flavonoids, alkaloids, tannins, and saponins, while the antioxidant test activity of robusta coffee beans extracts shows differences based on the results of statistical tests of linear regression analysis with the IC50 value the highest antioxidant content was inorganic coffee roasted bean extract only 14.0629 ppm compared to the organic roasted extract with a value of 30.6159 ppmKeywords: Robusta Coffee (Coffea canophora), Phytochemical Screening, DPPH MethodABSTRAKKopi bubuk adalah biji kopi yang telah disangrai digiling atau ditumbuk sehingga mempunyai bentuk halus. Tujuan dari penelitian ini adalah untuk mengetahui kandungan senyawa dalam ekstrak biji sangrai kopi robusta (Coffe canephora) dari tanaman hasil pemupukan organik dan anorganik, dan mengetahui perbedaan senyawa antara hasil pemupukan organik dan anorganik. Karakteristik skrining fitokimia dilakukan secara kualitatif yang dilakukan terhadap alkaloid, flavonoid, tanin, terpenoid dan saponin dan aktivitas antioksidan dilakukan dengan metode DPPH (1,1-difenil-2-pikrihidrazil). Hasil uji karakteristik skrining fitokimia menunjukkan bahwa ekstrak biji sangrai kopi robusta dari hasil pemupukan oganik dan anorganik keduanya sama mengandung senyawa flavonoid, alkaloid, tanin, dan saponin,  sedangkan pada aktifitas uji antioksidan ekstrak biji sangrai kopi robusta menunjukan perbedaan berdasarkan hasil uji statistik analisis regresi linear dengan nilai IC50 kadar antioksidan paling tinggi adalah ekstrak biji sangrai kopi anorganik hanya 14,0629 ppm dibandingkan dengan ekstrak sangrai dari organik dengan nilai 30,6159 ppm.Kata kunci : Kopi Robusta (Coffea canophera), Skrining Fitokimia, Metode DPPH


2000 ◽  
Vol 15 (12) ◽  
pp. 2758-2769 ◽  
Author(s):  
Michael Lane ◽  
Reinhold H. Dauskardt ◽  
Anna Vainchtein ◽  
Huajian Gao

The effects of plasticity in thin copper layers on the interface fracture resistance in thin-film interconnect structures were explored using experiments and multiscale simulations. Particular attention was given to the relationship between the intrinsic work of adhesion, Go, and the measured macroscopic fracture energy, Gc. Specifically, the TaN/SiO2 interface fracture energy was measured in thin-film Cu/TaN/SiO2 structures in which the Cu layer was varied over a wide range of thickness. A continuum/FEM model with cohesive surface elements was employed to calculate the macroscopic fracture energy of the layered structure. Published yield properties together with a plastic flow model for the metal layers were used to predict the plasticity contribution to interface fracture resistance where the film thickness (0.25–2.5 μm) dominated deformation behavior. For thicker metal layers, a transition region was identified in which the plastic deformation and associated plastic energy contributions to Gc were no longer dominated by the film thickness. The effects of other salient interface parameters including peak cohesive stress and Go are explored.


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