TY - GEN
T1 - Surface warpage measurement of diamond grid disk by shadow Moiré method
AU - Chen, Terry Yuan Fang
AU - Chen, Jian Shiang
PY - 2011
Y1 - 2011
N2 - Diamond grid disk dresser is frequently employed to remove the accumulated debris lest the polishing surface glazes. The surface warpage of diamond grid disk must be small enough to assure the flatness of polished wafers during chemical mechanical planarization process. In this study, phase-shifted shadow moiré method was employed to measure the surface warpage of diamond grid disks. To eliminate erroneous bright or black spots caused by the diamond grids, a novel method is proposed by selecting proper threshold values from the addition of four phase-shifted images, and from the grey-level difference between the addition of phases 0 and π images and the addition of phases π/2 and 3π/2 images. Test of the proposed method on real specimens show that the erroneous bright and black spots can be effectively identified and patched. Thereafter the phase can be unwrapped successfully to obtain the surface profile and thus the warpage of specimens.
AB - Diamond grid disk dresser is frequently employed to remove the accumulated debris lest the polishing surface glazes. The surface warpage of diamond grid disk must be small enough to assure the flatness of polished wafers during chemical mechanical planarization process. In this study, phase-shifted shadow moiré method was employed to measure the surface warpage of diamond grid disks. To eliminate erroneous bright or black spots caused by the diamond grids, a novel method is proposed by selecting proper threshold values from the addition of four phase-shifted images, and from the grey-level difference between the addition of phases 0 and π images and the addition of phases π/2 and 3π/2 images. Test of the proposed method on real specimens show that the erroneous bright and black spots can be effectively identified and patched. Thereafter the phase can be unwrapped successfully to obtain the surface profile and thus the warpage of specimens.
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U2 - 10.1117/12.905441
DO - 10.1117/12.905441
M3 - Conference contribution
AN - SCOPUS:84855313456
SN - 9780819479402
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Seventh International Symposium on Precision Engineering Measurements and Instrumentation
T2 - 7th International Symposium on Precision Engineering Measurements and Instrumentation
Y2 - 7 August 2011 through 11 August 2011
ER -