Full-blown process excursions that affect every wafer are comparatively easy for fabs to detect and fix. However, “onesie-twosie,” lower-volume excursions can go unresolved for months or even years.

Leading chipmakers TSMC and Samsung are producing 5nm devices in high volume production and TSMC is forging ahead with plans for first 3nm silicon by year end. But to meet such aggressive targets, ...