Interconnect processes

Which technique deposits a Cu alloy with a small addition of manganese or similar and, through annealing, lets a thin barrier form spontaneously at the interface with the dielectric?

  1. ASelf-forming barrier
  2. BLOCOS
  3. CIon implantation
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Answer: A. Self-forming barrier

With a Cu-Mn alloy seed, annealing drives Mn to the interface, where it reacts with the dielectric to form a very thin barrier such as MnSiOx. Because less separate barrier metal needs to be deposited, it is expected to increase the share of low-resistance Cu in narrow wires and vias.

  • A. Correct. A barrier forms spontaneously at the interface.
  • B. LOCOS is isolation by selective oxidation.
  • C. Ion implantation introduces impurities.
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More Interconnect processes questions

  1. For long, wide wires such as the clock network of a chip running at several GHz, which wire property must be considered in addition to resistance and capacitance?
  2. What is the main reason the wiring material of advanced LSIs was changed from aluminum (Al) to copper (Cu)?
  3. Which correctly describes the damascene process commonly used to form copper wiring?
  4. What is the main purpose of using low-k (low dielectric constant) materials for interlayer dielectrics?
  5. What is the main purpose of barrier metals such as Ta and TaN in copper wiring?