https://arstechnica.com/gadgets/2021/04/chipmaker-says-it-will-ramp-up-production-of-older-28nm-chips/

United Microelectronics Corporation (UMC), the world’s fourth-largest contract chipmaker, is expanding its capacity to produce mature technology chips in exchange for financial guarantees, in response to the shortage gripping the global semiconductor supply chain.

UMC said it would add capacity for manufacturing 20,000 wafers a month at 28 nm, one of the process technology nodes worst-hit by the global chip shortage, at an existing fabrication plant, or “fab,” in Tainan.