Interconnect processes

Which is closest to the resistivity of copper (Cu) at room temperature? (Bulk value)

  1. AAbout 17 Ω·cm
  2. BAbout 1.7 mΩ·cm
  3. CAbout 1.7 µΩ·cm
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Answer: C. About 1.7 µΩ·cm

Bulk copper has a resistivity of about 1.7 µΩ·cm at room temperature, lower than aluminum (about 2.7 µΩ·cm). In very narrow wires, however, electron scattering at surfaces and grain boundaries makes the effective resistivity higher.

  • A. About 17 Ω·cm is a semiconductor-level resistivity, far too large for a metal.
  • B. About 1.7 mΩ·cm is about 1,000 times copper's resistivity.
  • C. Correct. Copper is about 1.7 µΩ·cm.
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More Interconnect processes questions

  1. Which set correctly lists the main properties required of LSI wiring materials?
  2. What is the basic role of the interlayer dielectric that fills the space between wires?
  3. Why has an Al-Cu alloy with about 0.5% copper been used for aluminum wiring?
  4. What is the phenomenon called in which electroplated Cu films, simply left at room temperature, grow larger grains over time and drop in resistivity?
  5. What is the main purpose of the design practice of placing two or more vias, rather than one, wherever possible to connect upper and lower wires?