Patterning 180nm CopperOxide Dual Damascene Baseline with 193nm Resists

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Patterning 180nm Copper-Oxide Dual Damascene
Baseline with 193nm Resists

• Abstract authors Vivek Bakshi and Gregory Smith
• Advanced Tool Development Facility, International
  SEMATECH, Inc. USA
• ELEC7730
• Presented By Hongtao Ma

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Objective and Approach

• Using thinner resist (193nm)for etching oxide
  dual damascene baseline.
• Via first Dual Damascene mathod to form the
  metallization

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Dual Damascene
http//www.semiconductors.net/technical/damascene_
copper.htm
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Via First Method
In the via-first approach, the trench is
patterned and etched after the via is
formed. Ref.http//courses.nus.edu.sg/course/phywe
ets/Projects99/Copper/damascene.htm
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Etching process
After etching the wafer will be ready for
barrier and seed metal deposition,, plating,
annealing and CMP to form two level metal
structure.
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Etchant

• High etch rate chemistry was used for etching of
  bottom oxide to form good via profile
• Higher selectivity etchant was used to etch
  nitride due to the limited resist available for
  the etchant.

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Yields vs the via sizes with 248nm resist
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Yield and resistance vs Via Size with 193nm resist
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Conclusions

• High etch rate chemistry was used for etching
  oxide, high selectivity etchant was used for
  etching nitride.
• Yield of various via chains drops with the via
  sizes

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References

• 248nm and 193nm lithography for damascene
  patterning Mireille Maenhoudt, Ivan Pollentier,
  Vincent Wiaux, Diziana Vangoidsenhoven, Kurt
  Ronse, IMEC, Leuven, Belgium.
• Fine-tuning the process The status of 193nm
  technology
• James Beach, Sri Satyanarayana, Arnie
  Ford, Vivek Bakshi International Sematech,
  Austin, Texas
• 3. A Novel Approach To Dual Damascene Patterning
  Makarem Hussein, Sam Sivakumar, Ruth Brain,
  Bruce Beattie, Phi Nguyen, and Mark Fradkin