Interconnect processes

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?

  1. ATo keep the connection even if one via fails, improving yield and reliability
  2. BTo make the chip larger
  3. CTo increase wiring capacitance
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Answer: A. To keep the connection even if one via fails, improving yield and reliability

Process variation can make vias open or high-resistance. Placing multiple vias (redundant vias) where space allows keeps the connection even if one fails, lowers resistance and improves electromigration resistance.

  • A. Correct. Redundancy improves yield and reliability.
  • B. It is not meant to enlarge the chip.
  • C. Increasing capacitance is not the purpose.
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More Interconnect processes questions

  1. Which term refers to the contacts and local interconnects that connect the transistors to the multilevel wiring?
  2. In scaled multilevel wiring, what is the main reason via resistance has become a problem?
  3. Which statement about the capacitance of a wire is correct?
  4. What is the effect of increasing a wire's thickness (height) without changing its width?
  5. In chips using mechanically weak low-k films, what is the problem called in which stress during packaging cracks or delaminates the films?