TSMC's utilization rate for 28nm and 20nm reportedly fell as low as 70 percent and 60 percent, respectively, in Q2 2015 due to lowered smartphone demand.
Decelerating smartphone demand has discouraged chip providers from placing orders with their foundry partners since the second quarter, the sources said. Foundries like United Microelectronics (UMC) and Globalfoundries have seen their 28nm customers cut orders particularly for baseband chips, the sources indicated.
Also facing a cutback of orders from its key mobile chip clients, TSMC has lowered its wafer quotes for 28nm and 20nm process technologies as much as 10%, the sources suggested.