• Proceedings of the KSME Conference
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• 2004.04a
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• pp.36-41
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• 2004

A method to measure the interfacial toughness of film/substrate by nanoindenter is proposed. As the thickness of the film decreases, the measurement of the interfacial toughness requires the more sophisticated equipment such as nanoindenter. In this study, the nanoindenter is applied to the substrate near the interface of film/substrate in the direction perpendicular to the normal of the interface, causing the cohesive fracture of the substrate, followed by the interfacial cracking. The specimen of Cu($0.56 {\mu}m$)/Si(530 ${\mu}$) are made by sputtering the copper onto the silicon wafer. By scratching the copper surface, we can make the easy interfacial cracking during the nanoindentation. It is found that the averaged values of the interfacial toughness of the Cu/Si is $0.664{\pm}0.3\;J/m^2$ . The phase angle of the specimen in this study is ${\psi}{\simeq}-36.8^{\circ}$, computed by the method of Suo and Hutchinson.[1]

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.607-608
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• 2008

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.2
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• pp.69-75
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• 2004

In this paper, we propose the shape of extremely small thrust VCM for application of the Nanoindenter, which enables control of very small force and displacement. We performed optimization of the VCM shape using conjugated gradient method. And the purposes of optimization are the minimization of the permanent magnet size for the efficient systems, minimization of deviation of flux density from the air gap for operate on regular thrust and a linearization of thrust for a good control characteristic. The finite element method is used for characteristic analysis. The node moving method is used to redundant changes of design variables. As a result, the VCM produces a yew small force by the difference of flux density of lower part from higher one. Also, in a wide range of current (0［A］-1［A］), the VCM produces linear driving thrust by saturating the magnetic circuit path and operate on regular thrust by minimizing deviation of flux density of the air gap.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.577-579
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• 2002

Propose of this paper is VCM (voice coil motor) design for application of Nanoindenter, which enable control of extremely small force and displacement. This paper present the VCM shape to produce a very small force by the difference of flux density of lower part from higher one. In wide range of current. VCM produces linear driving force and operate on regular thrust having maximum displacement(100um) was practiced.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.24-31
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• 2004

The objective of this work is to suggest a mastless pattern fabrication technique using the combination of machining by Nanoindenter(equation omitted) XP and HF wet etching. Sample line patterns were machined on a borosilicate surface by constant load scratch (CLS) of the Nanoindenter(equation omitted) XP with a Berkovich diamond tip, and they were etched in HF solution to investigate chemical characteristics of the machined borosilicate surface. All morphological data of scratch traces were scanned using atomic force microscope (AFM).

• Transactions of Materials Processing
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• v.12 no.7
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• pp.640-646
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• 2003

The nanoprobe based on lithography, mainly represented by SPM based technologies, has been recognized as potential application to fabricate the surface nanostructures because of its operational versatility and simplicity. The objective of the work is to suggest new mastless pattern fabrication technique using the combination of machining by nanoindenter and KOH wet etching. The scratch option of the nanoindenter is a very promising method for obtaining nanometer scale features on a large size specimen because it has a very wide working area and load range. Sample line patterns were machined on a silicon surface, which has a native oxide on it, by constant load scratch (CLS) of the Nanoindenter with a Berkovich diamond tip, and they were etched in KOH solutions to investigate chemical characteristics of the machined silicon surface. After the etching process, the convex structure was made because of masking effect of the affected layer generated by nano-scratch. On the basis of this fact, some line patterns with convex structures were fabricated. Achieved patterns can be used as a mold that will be used for mass production processes such as nanoimprint or PDMS molding process. All morphological data of scratch traces were scanned using atomic force microscope (AFM).

• Journal of the Korean Vacuum Society
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• v.19 no.5
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• pp.360-364
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• 2010

Most research groups used two analysis methods (spectroscopy and nanotribology) to measure the mechanical properties of nano-materials: NMR (Nuclear Magnetic Resonance), IR (Infrared Spectroscopy), Raman Spectroscopy as the spectroscopy method and AFM (Atomic Force MicroScope), EFM (Electrostatic Force Microscope), KFM (Kelvin Force Microscope), Nanoindenter as the nanotribological one. Among these, the nano-indentation technique particularly has been recognized as a powerful method to measure the elastic modulus and the hardness. However, this technique are prone to considerable measurement errors with pressure conditions during measurement. In this paper, we measured the change of elastic modulus and hardness of an Al single crystal with the change of load, hold, and unload time, respectively. We found that elastic modulus and hardness significantly depend on load, hold, and unload time, etc. As the indent time was shortened, the elastic modulus value decreased while the hardness value increased. In addition, we found that elastic modulus value was more sensitive to indent load, hold, and unload time than the hardness value. We speculate that measurement errors of the elastic modulus and the hardness originate from the residual stress during indenting test. From our results, the elastic modulus was more susceptible to the residual stress than the hardness. Thus, we find that the residual stress should be controlled for the minimum measurement errors during the indenting test.

• Proceedings of the Korean Vacuum Society Conference
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• 1997.02a
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• pp.110-111
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• 1997

• Transactions of Materials Processing
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• v.13 no.4
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• pp.374-381
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• 2004

In this study, the deformation behavior of semi-solid Al-Si alloy was investigated by nanoindenter as a part of the research on the surface crack behavior in thixoformed automobile component. The microstructure of semi-solid Al-Si alloy consists of primary and eutectic regions. In eutectic regions the crack initiation begins with initial fracture of the eutectic silicon particles and inside other intermetallic phases. Nano-deformation characteristics in the eutectic and primary phase of semi-solid aluminium alloy were investigated through the nano-indentation experiments and the AFM observation. In addition, mechanical properties of each region were investigated and compared with each other.

• Journal of the Korean Vacuum Society
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• v.20 no.3
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• pp.200-204
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• 2011

In this paper, we deposited the tungsten carbon nitride (W-C-N; nitrogen gas flow of 2 sccm) and tungsten carbon (W-C) thin film on silicon substrate using rf magnetron sputter. Then the thin films annealed at $800^{\circ}C$ during 30 minute ($N_2$ gas ambient) for thermal damage. Nano-indenter was executed 16 points on thin film surface to measure the thermal stability, and we also propose the elastic modulus and the Weibull distribution, respectively. This nanotribology method provides statistically reliable information. From these results, the W-C-N thin film included nitrogen gas flow is more stable for film uniformities, physical properties and crystallinities than that of not included nitrogen gas flow.