The yield issues affect 12nm and 16nm chips produced for NVIDIA, MediaTek, and HiSilicon, as well as smaller clients. TSMC confirmed the issue but said it doesn't affect its first quarter financial guidance given on January 17, 2019.
"TSMC has discovered that a shipment of certain chemical used in the manufacturing process deviated from specifications and caused wafers to have lower yields," said the foundry house in a filing with Taiwan's stock exchange late Monday night in response to the media reports.In a different statement, the foundry elaborated that the yield problem was discovered on January 19, and that the chemical was supplied by a vendor with a good, multi-year track record.
It said the problem was caused by a shipment of photoresist material provided by a vendor with many years of experience and a good track record in supplying to TSMC. But that particular batch of shipment "is significantly below the quality of its previous shipments," TSMC said.Via: DigiTimes
The foundry house said it immediately stopped using the material and notified all affected customers. It did not name the customers.