LSI design flow and EDA

What is the main purpose of placing dummy patterns that do not function as circuits in empty areas of the layout?

  1. ATo decorate the chip
  2. BTo even out pattern density and suppress variation in CMP and etch results
  3. CTo increase capacitance between wires
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Answer: B. To even out pattern density and suppress variation in CMP and etch results

If pattern density varies greatly from place to place, CMP removal and etch rates vary, making film thickness and dimensions nonuniform. Placing dummy patterns (dummy fill) in empty areas to even out density suppresses this variation.

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More LSI design flow and EDA questions

  1. For layouts intended for double patterning, which correctly describes how design tools assign patterns?
  2. Which correctly describes a netlist?
  3. In logic synthesis and static timing analysis, what is the description of timing conditions such as clock period and I/O delays called?
  4. Which are the typical formats of layout data handed to manufacturing for mask making?
  5. Which step at the start of place and route decides the rough placement of large circuit blocks, I/O pins, power wiring and the like?