The newer fabrication technologies provide substantial performance advantages of increased speed and reduced power. They also provide the disadvantage of increased mask cost. And this makes many opportunities with lower volumes uneconomical.
But there is a way around the mask costs. Most foundries offer shuttle runs. A shuttle run divides the mask into multiple regions, and puts a different customer's design into each region. The mask cost is shared by all of the customers, and is proportional to the area used by each design. The fab then runs a lot of wafers with the shuttle mask set. When the run is completed, the wafer is divided up, and each customer receives a small number of die. While the individual die is expensive, the total cost is much less than using a dedicated mask set and wafer run. Additional wafers can be run using the same mask set, allowing small to medium volumes.
The economics are interesting. Assume a $500K total mask set charge, and a $4000 wafer cost. A 5x5 mm die represents 1/16th of the mask area, and would appear 165 times on a 300 mm shuttle wafer. The mask charge is reduced from $500K to $32K, while the die cost rises from $1.50 to $24.00. This makes the volume breakeven point for buying a full mask set be 20K units. There are a lot of opportunities that have volumes much less than 20K units.
The economic feasibility exists. We now have to productize it in order to offer low cost ASICs in the 65 to 180 nm range. And that will be the topic for a future newsletter.