Thin Film Decohesion and Its Measurement

1995 ◽  
Vol 383 ◽  
Author(s):  
A. Bagchi ◽  
A. G. Evans

ABSTRACTThe mechanics of thin films are used to define quantitative procedures for predicting interface decohesion motivated by residual stress. The emphasis is on the role of the interface debond energy, especially methods for its accurate and reliable measurement. Experimental results are reviewed and possible mechanisms are discussed.

1996 ◽  
Vol 457 ◽  
Author(s):  
R. Banerjee ◽  
X. D. Zhang ◽  
S. A. Dregia ◽  
H. L. Fraser

ABSTRACTNanocomposite Ti/Al multilayered thin films have been deposited by magnetron sputtering. These multilayers exhibit interesting structural transitions on reducing the layer thickness of both Ti and Al. Ti transforms from its bulk stable hep structure to fee and Al transforms from fee to hep. The effect of ratio of Ti layer thickness to Al layer thickness on the structural transitions has been investigated for a constant bilayer periodicity of 10 nm by considering three different multilayers: 7.5 nm Ti / 2.5 nm Al, 5 nm Ti / 5 nm Al and 2.5 nm Ti / 7.5 nm Al. The experimental results have been qualitatively explained on the basis of a thermodynamic model. Preliminary experimental results of interfacial reactions in Ti/Al bilayers resulting in the formation of Ti-aluminides are also presented in the paper.


2015 ◽  
Vol 51 (6) ◽  
pp. 1143-1146 ◽  
Author(s):  
Monika Warzecha ◽  
Jesus Calvo-Castro ◽  
Alan R. Kennedy ◽  
Alisdair N. Macpherson ◽  
Kenneth Shankland ◽  
...  

Sensitive optical detection of nitroaromatic vapours with diketopyrrolopyrrole thin films is reported for the first time.


1989 ◽  
Vol 4 (5) ◽  
pp. 1209-1217 ◽  
Author(s):  
K. Maex ◽  
G. Ghosh ◽  
L. Delaey ◽  
V. Probst ◽  
P. Lippens ◽  
...  

The thermodynamic equilibrium of structures consisting of a thin film silicide (TiSi2 or CoSi2) on doped Si (with As or B) is investigated. Isothermal sections of the ternary phase diagrams for Ti–Si–B, Co–Si–B, Ti–Si–As, and Co–Si–As have been evaluated, indicating the stability of high B concentrations in Si underneath a CoSi2 layer, the instability of high As concentrations in Si underneath a CoSi2 layer, and of B and As concentrations underneath a TiSi2 layer. The obtained thermodynamic predictions agree very well with experimental results (i) on the redistribution of dopants during silicide formation, (ii) on the diffusion of dopants from an ion implanted silicide, and (iii) on the stability of highly doped regions underneath the silicide, both for the case of TiSi2 and CoSi2. It is shown that even though the inaccuracy of reported thermodynamic data is substantial, thermodynamic calculations provide a useful guidance and are consistent with the experimental results.


1999 ◽  
Vol 596 ◽  
Author(s):  
Tingkai Li ◽  
Sheng Teng Hsu ◽  
Yufei Gao ◽  
Mark Engelhard

AbstractThree kinds of oriented electrodes of Pt, Ir and Pt/Ir electrodes were prepared using electron beam evaporation techniques for deposition of PZT thin films. An oxide MOCVD reactor with liquid delivery system was used for the growth of PZT thin films. [Pb(thd)2], Zr(TMHD)4 and Ti(IPO)4 were dissolved in a mixed solvent of tetrahydrofuran or butyl ether, isopropanol and tetraglyme to form a precursor source. The deposition temperature and pressure were 500 - 650°C and 5 - 10 Torr, respectively. The experimental results showed PZT thin film deposited on various electrodes had different phase formation, microstructure and ferroelectric property. The X-ray patterns showed the perovskite phase of PZT was formed on both Ir and Pt/Ir electrodes at 550°C. The grain size of the PZT thin film increases after a further, higher temperature annealing. The as-deposited PZT thin film on Pt electrode exhibits pyrochlore phase at 550°C. The phase is transformed to perovskite phase after 650°C annealing. The experimental results also indicated that the MOCVD PZT thin film on Pt/Ir exhibits better ferroelectric and electrical properties compared to those deposited on Pt and Ir electrodes. A 300 nm thick PZT thin film on Pt/Ir electrode has a square, well saturated, and symmetrical hysteresis loop with 2Pr value of 40 μC/cm2 and 2Ec of 73 kV/cm at an applied voltage of 5 V. The hysteresis loop of the PZT thin film is almost saturated at 2 V. The leakage current of the film is 6.16 × 10−7 A/cm2 at 100 KV/cm. The electrode effects on ferroelectric properties of PZT thin films also have been investigated.


2003 ◽  
Vol 795 ◽  
Author(s):  
Alex A. Volinsky ◽  
Dirk C. Meyer ◽  
Tilmann Leisegang ◽  
Peter Paufler

ABSTRACTWhile there are many stress relief mechanisms observed in thin films, excessive residual and externally applied stresses cause film fracture. In the case of tensile stress a network of through-thickness cracks forms in the film. In the case of compressive stress thin film buckling is observed in the form of blisters. Thin film delamination is an inseparable phenomenon of buckling. The buckling delamination blisters can be either circular, straight, or form periodic buckling patterns commonly known as telephone cord delamination morphology.While excessive biaxial residual stress is the key for causing thin film fracture, either in tension, or compression, it is the influence of the external stress that can control the final fracture pattern. In this paper we consider phone cord buckling delamination observed in compressed W/Si and TiWN/GaAs thin film systems, as well as spiral and sinusoidal though-thickness cracks observed in Mo/Si multilayers under 3-point high-temperature bending in tension.


Author(s):  
Jiatong Liu ◽  
Ken Suzuki ◽  
Hideo Miura

In a three-dimensional (3D) packaging systems, the interconnections which penetrate stacked silicon chips have been employed. Such interconnection structure is called TSV (Through Silicon Via) structure, and the via is recently filled by electroplated copper thin film. The electroplated copper thin films often consist of fine columnar grains and porous grain boundaries with high density of defects which don’t appear in conventional bulk material. This unique micro texture has been found to cause the wide variation of physical and chemical properties of this material. In the TSV structure, the shrinkage of the copper thin film caused by thermal deformation and recrystallization of the unique texture during high-temperature annealing is strictly constrained by surrounding rigid Si and thus, high tensile residual stress remains in the thin film after thermal annealing. High residual stress should give rise to mechanical fracture of the interconnections and the shift of electronic function of thin film devices formed in Si. Therefore, the residual stress in the interconnections should be minimized by controlling the appearance of the porous boundaries during electroplating for assuring the longterm reliability of the interconnections. As the lattice mismatch between Cu and its barrier film (Ta) is as larger as 18%, which is the main reason for the fine columnar structures and porous grain boundaries, it is necessary to control the underlayer crystallinity to improve the crystallinity of electroplated copper thin films. In this study, the effective method for controlling the crystallinity of the underlayer was investigated by improving the atomic configuration in the electroplated copper thin film. The result showed that by controlling the crystallinity of underlayer, crystallinity of electroplated copper thin films can be improved, the mechanical properties of thin films was improved and thus, stability and lifetime of electroplated copper interconnections can be improved.


CrystEngComm ◽  
2014 ◽  
Vol 16 (27) ◽  
pp. 6033-6038 ◽  
Author(s):  
Lander Rojo ◽  
Irene Castro-Hurtado ◽  
María C. Morant-Miñana ◽  
Gemma G. Mandayo ◽  
Enrique Castaño

This work present the first steps of thin film solid state electrochemical devices development based on Li2CO3.


RSC Advances ◽  
2015 ◽  
Vol 5 (69) ◽  
pp. 55648-55657 ◽  
Author(s):  
M. Younas ◽  
Junying Shen ◽  
Mingquan He ◽  
R. Lortz ◽  
Fahad Azad ◽  
...  

Room temperature ferromagnetism (FM) of these thin film samples are highly tuneable by the simultaneous presence of CuO nanophases and multivalent Cu and Vö concentrations.


2014 ◽  
Vol 70 (a1) ◽  
pp. C724-C724
Author(s):  
Christoph Genzel

The most important advantage of energy dispersive (ED) diffraction compared with angle dispersive methods is that the former provides complete diffraction patterns in fixed but arbitrarily selectable scattering directions. Furthermore, in experiments that are carried out in reflection geometry, the different photon energies E(hkl) of the diffraction lines in an ED diffraction pattern can be taken as an additional parameter to analyze depth gradients of structural properties in the materials near surface region. For data evaluation advantageous use can be made of whole pattern methods such as the Rietveld method, which allows for line profile analysis to study size and strain broadening [1] or for the refinement of models that describe the residual stress depth distribution [2]. Concerning polycrystalline thin films, the features of ED diffraction mentioned above can be applied to study residual stresses, texture and the microstructure either in ex-situ experiments or in-situ to monitor, for example, the chemical reaction pathway during film growth [3]. The main objective of this talk is to demonstrate that (contrary to a widespread opinion) high energy synchrotron radiation and thin film analysis may fit together. The corresponding experiments were performed on the materials science beamline EDDI at BESSY II which is one of the very few instruments worldwide that is especially dedicated to ED diffraction. On the basis of selected examples it will be shown that specially tailored experimental setups allow for residual stress depth profiling even in thin films and multilayer coatings as well as for fast in situ studies of film stress and microstructure evolution during film growth.


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