Yield and quality control

With all else equal, about how many times larger does wafer area become when wafer diameter is increased from 200 mm to 300 mm?

  1. AAbout 2.25 times
  2. B1.5 times
  3. C3 times
Show answer and explanation

Answer: A. About 2.25 times

Area is proportional to the square of the diameter, so it becomes (300 / 200)² = 1.5² = 2.25 times. In practice, the share of partial chips at the edge decreases, so the number of chips obtained is more than 2.25 times. This is why larger wafers help reduce cost.

Practice this topic Back to topic

More Yield and quality control questions

  1. In a control chart, which is an example that should be judged abnormal even though all points are within the control limits?
  2. In the Poisson model Y = exp(−D × A), with defect density D = 0.1 /cm² and chip area A = 1 cm², approximately what is the yield?
  3. Among defects on a wafer, what are those called that actually cause electrical failure of a chip?
  4. Which chart divides data into intervals and shows the frequencies as bars to see the shape of the distribution of variation?
  5. Which process capability index is used when the process mean is offset from the center of the specification?