Measurement of Adhesion at Film -Substrate Interfaces by Constant Depth Scratch Testing

1994 ◽  
Vol 338 ◽  
Author(s):  
I. Dutta ◽  
D. P. Lascurain ◽  
E. D. Secor

ABSTRACTQuantitative tests for interfacial adhesion between films and substrates are of criticalimportance in micro-electronic applications. However, many of the available tests are applicable to a limited array of materials systems, or are experimentally complex. In thispaper, a constant depth scratch test, which has been designed to circumvent the limitations associated with currently available tests, is presented along with theoretical developments for the quantification of interfacial shear strength. Because of a fixed scratchgeometry, the test is amenable to straightforward analytical formulations unlike other versions of scratch tests. It is unique in its experimental simplicity, and allows evaluation of interface strength as function of position on the sample. Sample outputs from the test based on Cr films on glass substrates are presented.

1995 ◽  
Vol 390 ◽  
Author(s):  
I. Dutta ◽  
J. C. Campbell

ABSTRACTA constant depth scratch test (CDST) has been recently developed to quantify the shear strength of film-substrate interfaces. This test is capable of measuring interfacial adhesion as a function of position on the sample surface during a continuous scratch. Unlike many of the currently available tests which are applicable to a limited array of materials systems, or are experimentally complex, this test is quite versatile, and is relatively straightforward to conduct and interpret because of the constant depth geometry. The theoretical basis and the experimental set-up for the test have been previously presented. In this paper, extensions of the theoretical formulation to account for different debonding behaviors of different film-substrate systems are discussed. Experimental results generated with a number of systems, including chromium on glass, gold on aluminum nitride, gold on aluminum nitride with a chromium inter-layer, and polycrystalline diamond on aluminum nitride are presented.


Author(s):  
Vincent Le Houérou ◽  
Leandro Jacomine ◽  
Christian Gauthier

In most cases, scratching of the surface of a polymeric glass elicits brittle behavior and industrial solutions like coating have been successfully used to improve the scratch resistance. The origin of the success of the coating technique is still of great research interest since one of the limitations of this technique is the risk of cracking and chipping. In terms of interfacial adhesion characterization, a wide variety of methods have been used to assess this property of material systems. Nevertheless, the adhesion of coatings still remains to be successfully determined in a test which can reproduce the damage undergone by the coated surface during its real lifetime. In this context, scratch test constitutes a good candidate. The present study deals with the scratching technique as an interfacial adhesion measurement in coated systems. Using a single-asperity scratching device allowing in-situ observation of the scratch, the fracture of a thin nano-composite coating deposited on its substrate was investigated under different conditions of temperature and scratching speed. Four types of fracture kinetics were observed depending on these two variables. One of these exhibits a stable blister growth at the same speed as the movement of the indenter over hundreds micrometers. This slow and extensive growth of a blister was obtained at 80 °C at a scratching speed of 10 μm/s. When the blister has reached a certain size, it propagates with the indenter without increasing further in size: it constitutes the steady state blister growth. A variational form of the energy balance of a blistering process is proposed, which permits to assess the adhesion of the system. Actually, the energy spent in the delamination process can be determined by following the delaminated area during the blistering process with regard to the scratching distance. The main difficulty is to estimate the energy dissipated in plastic flow. Different tests were conducted with various indenters: spheres with different radius and roughness. Thanks to this multi-criterion approach, it was possible to fit a unique value of the adhesion in the case of experimental stable blistering growths. The results are discussed with regard to reliability and probe characteristics.


2003 ◽  
Vol 795 ◽  
Author(s):  
R. Hoy ◽  
P. van Essen ◽  
J.-D. Kamminga ◽  
G. C. A. M. Janssen ◽  
A. P. Ehiasarian

ABSTRACTHard CrNx coatings of various composition were deposited on hot work tool steel by means of reactive sputter deposition in an industrial PVD reactor. All deposited coatings (thickness 3–4 micron) were under compressive stress. The coatings were subjected to scratch testing with a diamond stylus. Two critical loads were determined. The first critical load, Lc1, indicates the onset of chipping and/or spalling. The second critical load, Lc2, indicates complete coating removal inside the track. Micrographs showing the coating failure are presented. Stoichiomeric CrN coatings outperform understoichiometric CrN0.6 coatings in scratch tests. It was found that for all specimens the coating-to-substrate adhesion is very good, independent on composition. Although the values of Lc1 and Lc2 are distinctly different, their dependence on composition is similar.


2011 ◽  
Vol 1297 ◽  
Author(s):  
Bo Zhou ◽  
Nicholas Randall ◽  
Barton Prorok

ABSTRACTScratch testing, as a mature technique for coating adhesion quantification, has been widely adopted by both industrial and academic fields in recent years. Following the urgent needs of very small materials characterization, nano-scratch testing has gradually replaced the traditional pull-off test for the study of ultra-thin film properties. In this research, the relationship between the adhesion strength and film/substrate mechanical properties was investigated to provide fundamental but crucial knowledge of the scratch mechanism. Scratch tests were performed on different film/substrate combinations using a Nano Scratch Tester with a sphero-conical diamond indenter. A progressive load mode was employed to cause coating failure during scratch on the film surface. The critical values of different failure mechanisms, such as cracking and delamination were accurately determined according to the scratch panorama image, penetration and residual depth data. In addition, the hardness (H) and modulus (E) values of the thin films and substrates were measured with an Ultra Nanoindentation Tester. The scratch critical failure loads were then plotted versus film/substrate H and E ratios. A unique relationship was found between these parameters that could help understand the true mechanism behind scratch adhesion and leverage this methodology to a new theoretical level.


2004 ◽  
Vol 471-472 ◽  
pp. 746-749
Author(s):  
Ai Xin Feng ◽  
Yong Kang Zhang ◽  
H.K. Xie ◽  
Lan Cai

The interfacial adhesion between thin film and substrate is often the predominant factor and chief target in determining the performance and reliability of thin film/substrate system. A new technique of laser scratch testing technique has been presented by the authors of the article to characterize the interfacial adhesion between film and substrate, which synthesizes the advantages of traditional scratching technique and laser measure technique. The failure procedure is studied detailedly in the article. On different failure step of the film/substrate system, there are different characteristic s of stress and strain, as well as the characteristic of thermal lensing effect, which can be used as the distinguishing rule of the bonding state of the film/substrate system.


1993 ◽  
Vol 2 (5) ◽  
pp. 096369359300200 ◽  
Author(s):  
H.D. Wagner ◽  
S. Ling

An energy balance approach is proposed for the single fibre composite (or fragmentation) test, by which the degree of fibre-matrix bonding is quantified by means of the interfacial energy, rather than the interfacial shear strength, as a function of the fibre geometrical and mechanical characteristics, the stress transfer length, and the debonding length. The validity of the approach is discussed using E-glass fibres embedded in epoxy, both in the dry state and in the presence of hot distilled water.


2021 ◽  
pp. 095400832110089
Author(s):  
Ting Li ◽  
Zengxiao Wang ◽  
Hao Zhang ◽  
Yutong Cao ◽  
Zuming Hu ◽  
...  

The poor interfacial adhesion of aramid fiber and matrix limits the application of the final composites. In this study, a series of the sulfone-functionalized poly( p-phenylene terephthalamide) (SPPTA) copolymers were satisfactorily synthesized and the effects of polymerization conditions (contents of the additional monomer and the cosolvent LiCl, molar concentration and ratio of the monomer, reaction temperature and time) on the molecular weight of the copolymer were discussed. The introduction of the sulfone group in aromatic polyamides not only increased the polarity of poly( p-phenylene terephthalamide) (PPTA) but destroyed the regular arrangement of the molecular chains, which greatly improved the surface free energy and the solubility of the polymers in organic solvents. The polymer maintained excellent thermal and interfacial properties. Compared with the PPTA fiber/epoxy composites, the interfacial shear strength (IFSS) of SPPTA fiber-reinforced epoxy composites reached 43.5 MPa, with a significantly enhancement of 20.8%, implying that the study provided an effective method to achieve highly interfacial adhesion of aramid fiber-reinforced composites.


2006 ◽  
Vol 21 (2) ◽  
pp. 505-511 ◽  
Author(s):  
Lili Hu ◽  
Junlan Wang ◽  
Zijian Li ◽  
Shuang Li ◽  
Yushan Yan

Nanoporous silica zeolite thin films are promising candidates for future generation low-dielectric constant (low-k) materials. During the integration with metal interconnects, residual stresses resulting from the packaging processes may cause the low-k thin films to fracture or delaminate from the substrates. To achieve high-quality low-k zeolite thin films, it is important to carefully evaluate their adhesion performance. In this paper, a previously reported laser spallation technique is modified to investigate the interfacial adhesion of zeolite thin film-Si substrate interfaces fabricated using three different methods: spin-on, seeded growth, and in situ growth. The experimental results reported here show that seeded growth generates films with the highest measured adhesion strength (801 ± 68 MPa), followed by the in situ growth (324 ± 17 MPa), then by the spin-on (111 ± 29 MPa). The influence of the deposition method on film–substrate adhesion is discussed. This is the first time that the interfacial strength of zeolite thin films-Si substrates has been quantitatively evaluated. This paper is of great significance for the future applications of low-k zeolite thin film materials.


2004 ◽  
Vol 126 (2) ◽  
pp. 372-379 ◽  
Author(s):  
J. L. Bucaille ◽  
E. Felder ◽  
G. Hochstetter

An experimental and numerical study of the scratch test on polymers near their surface is presented. The elastoplastic response of three polymers is compared during scratch tests at large deformations: polycarbonate, a thermosetting polymer and a sol-gel hard coating composed of a hybrid matrix (thermosetting polymer-mineral) reinforced with oxide nanoparticles. The experiments were performed using a nanoindenter with a conical diamond tip having an included angle of 30 deg and a spherical radius of 600 nm. The observations obtained revealed that thermosetting polymers have a larger elastic recovery and a higher hardness than polycarbonate. The origin of this difference in scratch resistance was investigated with numerical modelling of the scratch test in three dimensions. Starting from results obtained by Bucaille (J. Mat. Sci., 37, pp. 3999–4011, 2002) using an inverse analysis of the indentation test, the mechanical behavior of polymers is modeled with Young’s modulus for the elastic part and with the G’sell-Jonas’ law with an exponential strain hardening for the viscoplastic part. The strain hardening coefficient is the main characteristic parameter differentiating the three studied polymers. Its value is equal to 0.5, 4.5, and 35, for polycarbonate, the thermosetting polymer and the reinforced thermosetting polymer, respectively. Firstly, simulations reveals that plastic strains are higher in scratch tests than in indentation tests, and that the magnitude of the plastic strains decreases as the strain hardening increases. For scratching on polycarbonate and for a penetration depth of 0.5 μm of the indenter mentioned above, the representative strain is equal to 124%. Secondly, in agreement with experimental results, numerical modeling shows that an increase in the strain hardening coefficient reduces the penetration depth of the indenter into the material and decreases the depth of the residual groove, which means an improvement in the scratch resistance.


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