Taiwan Semiconductor Manufacturing Company (TSMC) has confirmed that its 20nm wafer starts were delayed recently due to a specification issue of materials used in its CMP (chemical mechanical planarization) process. The issue has been resolved, and no shipments will be delayed, said the wafer foundry house.

　　TSMC began volume production of its 20nm process node at the beginning of 2014, focusing on Apple's A8 processors, according to industry sources.

　　The yield rate of the 20nm process has been ramped up significantly since then, reaching a level ahead of schedule, the sources noted.

　　While the production of 20nm wafers was delayed temporarily, no production lines have been shut down partially, and the CMP materials issue has been solved since TSMC has been maintaining a multi-source policy for the purchase of needed materials, TSMC said.

　　TSMC will continue to ramp its 20nm capacity quarter on quarter and expects sales of 20nm products to account for 20% of its total revenues in the fourth quarter of 2014.