Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
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3D Surface and Thickness Profile Measurements of Si Wafers by Using 6 DOF Stitching NIR Low Coherence Scanning Interferometry

6 DOF 정합을 이용한 대 영역 실리콘 웨이퍼의 3차원 형상, 두께 측정 연구

  • Park, Hyo Mi (Department of Photonic Engineering, Chosun University) ;
  • Choi, Mun Sung (Department of Photonic Engineering, Chosun University) ;
  • Joo, Ki-Nam (Department of Photonic Engineering, Chosun University)
  • 박효미 (조선대학교 광기술공학과) ;
  • 최문성 (조선대학교 광기술공학과) ;
  • 주기남 (조선대학교 광기술공학과)
  • Received : 2016.08.02
  • Accepted : 2016.12.12
  • Published : 2017.02.01
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Abstract

In this investigation, we describe a metrological technique for surface and thickness profiles of a silicon (Si) wafer by using a 6 degree of freedom (DOF) stitching method. Low coherence scanning interferometry employing near infrared light, partially transparent to a Si wafer, is adopted to simultaneously measure the surface and thickness profiles of the wafer. For the large field of view, a stitching method of the sub-aperture measurement is added to the measurement system; also, 6 DOF parameters, including the lateral positioning errors and the rotational error, are considered. In the experiment, surface profiles of a double-sided polished wafer with a 100 mm diameter were measured with the sub-aperture of an 18 mm diameter at $10\times10$ locations and the surface profiles of both sides were stitched with the sub-aperture maps. As a result, the nominal thickness of the wafer was $483.2{\mu}m$ and the calculated PV values of both surfaces were $16.57{\mu}m$ and $17.12{\mu}m$, respectively.

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References

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