Paper
7 July 1997 Importance of wafer flatness for CMP and lithography
Yuan Zhang, Lucian Wagner, Peter Golbutsov
Author Affiliations +
Abstract
Chemical mechanical planarization (CMP) is aimed at planarizing wafer surfaces in order to meet the tightening depth-of-focus requirements for advanced lithography. A simple method will be introduced which uses the site flatness requirement from the 1994 National Technology Roadmap for Semiconductors as a criterion to qualify post- CMP wafer flatness. Wafer dimensional data measured on a capacitance gauge were converted into local flatness with different site sizes according to the roadmap. The resulting site flatness was then subtracted from the required flatness threshold. The results suggest that current CMP technology improves wafer flatness from a 0.35 micrometers technology point of view. As the design rules shrink, however, more than half of the sites do not meet the 0.25 micrometers lithographic requirements even though there are flatness improvements due to CMP. Thus, much flatter wafers and more effective planarization technologies are needed to meet the challenges of next device generations.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yuan Zhang, Lucian Wagner, and Peter Golbutsov "Importance of wafer flatness for CMP and lithography", Proc. SPIE 3050, Metrology, Inspection, and Process Control for Microlithography XI, (7 July 1997); https://doi.org/10.1117/12.275916
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CITATIONS
Cited by 2 scholarly publications and 1 patent.
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KEYWORDS
Semiconducting wafers

Chemical mechanical planarization

Lithography

Semiconductors

Critical dimension metrology

Data conversion

Silicon

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