Assume a 15 cm diameter wafer has a cost of 12, contains 84 dies, and has 0.020 defects/cm². Assume a 20 cm diameter wafer has a cost of 15, contains 100 dies, and has 0.031 defects/cm².

1. Find the yield for both wafers.

2. Find the cost per die for both wafers.

3. If the number of dies per wafer is increased by 10% and the defects per area unit increases by 15%, find the die area and yield.

4. Assume a fabrication process improves the yield from 0.92 to 0.95. Find the defects per area unit for each version of the technology given a die area of 200 mm².