Re:Samsung Foundry: New $17B Fab in the USA by Late 2023
by baybal2 on Wednesday February 10, 2021 @07:28PM
(#26096730)
> Is there any reason they couldn’t just start with multipatterning 193nm immersion?
Time, yields, line size.
Quadruple patterning quadrupples the lithography steps counts. And quadrupples thermal cycles. Which adds more than 4x impact on the number of bad wafers.
100% - 2% * 4 != 100% * 0.98⁴
You need 4x the equipment to complete the same volume of wafers in the same time, which means 4x the line length.
Time, yields, line size.
Quadruple patterning quadrupples the lithography steps counts. And quadrupples thermal cycles. Which adds more than 4x impact on the number of bad wafers.
100% - 2% * 4 != 100% * 0.98⁴
You need 4x the equipment to complete the same volume of wafers in the same time, which means 4x the line length.