Visualization and Measurement of Contact Area by
                    Reflectivity

Diaconescu, Emanuel; Glovnea, Marilena

doi:10.1115/1.2345421

Cited by 7 publications

(3 citation statements)

References 1 publication

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“…Diaconescu and Glovnea have presented a method of visualizing and measuring the actual contact area by reflectivity at a millimeter contact area scale. 5) This millimeter length scale, however, is not appropriate for measuring pad-wafer contact area in CMP. Dual-emission laser-induced fluorescence (DELIF) has recently been adapted to measure pad-wafer contact in CMP.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Pad–Wafer Contact and Surface Topography in Chemical Mechanical Planarization Using Laser Confocal Microscopy

Sun

Zhuang

Borucki³

et al. 2010

Jpn. J. Appl. Phys.

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In this study, an optical method using laser confocal microscopy was developed to measure the surface contact area and topography of pads under a dry and static condition. A custom-made pad sample holder with a sapphire window and a miniature load cell was used to collect pad surface contact images at controlled loads. By extracting the black spots in the collected images, pad contact area and contact summit density were obtained. The analysis of a post polishing pad sample (8,289×921 µm2) showed that the contact area increased from 0.026 to 0.045% when the pressure increased from 2 to 4 psi and increased further to 0.059% when the pressure increased to 6 psi. The contact summit density also exhibited a linear increase with the applied pressure. The above results were consistent with the Greenwood and Williamson theory, which predicted a linear relationship between pad contact area and contact summit density. Laser confocal microscopy was also used to measure pad surface topography by establishing probability density functions (PDFs) of pad surface height.

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Section: Introductionmentioning

confidence: 99%

Characterization of Pad–Wafer Contact and Surface Topography in Chemical Mechanical Planarization Using Laser Confocal Microscopy

Sun

Zhuang

Borucki³

et al. 2010

Jpn. J. Appl. Phys.

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“…These include the use of pressure-sensitive surface transducers (e.g. references [7] and [8]), ultrasound detection [9], Raman spectroscopy [10][11][12], laser profilometry [13], etc. Spatial resolution and evaluation time (contact area scanning procedures) are the most limited parameters to obtain pressure distribution within lubricated contacts between non-smooth surfaces or contacts operated under non-steady-state conditions.…”

Section: Introductionmentioning

confidence: 99%

Effect of surface dents on contact pressure in elastohydrodynamic contacts

Křupka

Vrbka

Vaverka

et al. 2009

Proceedings of the Institution of Mechanical Engineers, Part J:

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Nowadays film thickness measurement techniques can provide precise data for the detailed studies of the behaviour of lubricated contacts including transient operational conditions. Contact pressure is in relation with deformation of rubbing surfaces, which can be derived from experimentally evaluated film thickness. Even though the pressure distribution evaluated from measured film thickness is very sensitive to its accuracy, this approach represents a powerful tool for elastohydrodynamic pressure determination; thanks to the relative wide availability of film thickness measurement techniques. Chromatic interferograms can be captured within a few microseconds so that this approach seems to be promising in obtaining relevant pressure data even within non-smooth lubricated contacts. This article presents the results of the effort to extend the applicability of the pressure-film thickness evaluation approach to the non-smooth surfaces. It was found that the main problem is to obtain the film thickness distribution within the whole contact including the inside portion of the deep surface features (e.g. dents). That is why the combination of film thickness data and undeformed dent topography was suggested to overcome these limitations. This approach was validated through the comparison with numerical solution using dented surface and was tested on selected dented contacts operated under thin film and very thin film lubrication conditions.

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“…Most previous studies on the pad surface micro-texture have been focused on the characterization methods and factors that affect pad surface contact area and topography. [3][4][5][6][7][8][9] For example, Elmufdi and Muldowney used confocal reflectance interference contrast microscopy to quantify the contact area between a pad and wafer under realistic polishing pressures and investigated the effect of pad material, conditioner type, and extent of conditioning on the pad surface contact area. 3,4) Sun et al employed laser confocal microscopy to measure the pad surface contact area as well as pad surface topography and studied the relation between contact area and contact summit density under different pressures.…”

mentioning

confidence: 99%

Effect of Pad Surface Micro-Texture on Removal Rate during Interlayer Dielectric Chemical Mechanical Planarization Process

Liao

Zhuang

Borucki³

et al. 2012

Jpn. J. Appl. Phys.

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The effect of pad surface micro-texture on removal rate in interlayer dielectric chemical mechanical planarization was investigated. Blanket 200mm oxide wafers were polished on a Dow â IC1000ä K-groove pad conditioned at two different conditioning forces. The coefficient of friction increased slightly (by 7%) while removal rate increased dramatically (by 65%) when conditioning force was increased from 26.7 to 44.5 N. Pad surface micro-texture analysis results showed that pad surface contact area decreased dramatically (by 71%) at the conditioning force of 44.5 N, leading to a sharp increase in the local contact pressure and resulting in a significantly higher removal rate.

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Visualization and Measurement of Contact Area by Reflectivity

Cited by 7 publications

References 1 publication

Characterization of Pad–Wafer Contact and Surface Topography in Chemical Mechanical Planarization Using Laser Confocal Microscopy

Characterization of Pad–Wafer Contact and Surface Topography in Chemical Mechanical Planarization Using Laser Confocal Microscopy

Effect of surface dents on contact pressure in elastohydrodynamic contacts

Effect of Pad Surface Micro-Texture on Removal Rate during Interlayer Dielectric Chemical Mechanical Planarization Process

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