Apparatus and method for measuring thickness variation of wax film
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United States of America Patent
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N/A
Issued Date -
Jul 21, 2005
app pub date -
Jun 4, 2004
filing date -
Jan 15, 2004
priority date (Note) -
Abandoned
status (Latency Note)
Importance
Abstract
An apparatus and a method for measuring the thickness of wax film layer, bonded to a semiconductor wafer, are disclosed. Furthermore, the invention disclosed allows the detection of particles, such as dust particles embedded in the surface of the wax film. The invention uses optical measurements based on coherent illumination, interference of the rays reflected by the two surfaces of the wax, and imaging means that produces an image where defected can easily be distinguished from and non-defected areas. The invention leads to higher yields and therefore lower costs generally during the fabrication of semiconductor components, and particularly during the polishing stage of the wafer.
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Patent Citation Ranking
- 4 Citation Count
- G01B Class
- 2.91 % this patent is cited more than
- 20 Age