Earlier this year, Apple and Taiwan Semiconductor Manufacturing Company (TSMC) inked a three-year deal for the chip manufacturer to produce A-series processors for iOS devices starting in 2014. While the move was seen as a strategic step away from relying on rival Samsung to produce the chips, it's now appearing that it is strictly a move toward diversifying supply away from a single source. The Verge, citing Korean daily Hankyung, says that production of the next-generation A8 chip will be handled primarily by TSMC with Samsung still grabbing about 30-40 percent of manufacturing.
Chipworks found that Samsung is the manufacturer of the A7 chip used in the iPhone 5s at this time, so Apple is still relying on the Korean manufacturer for all of the processors used in the flagship iPhone. For future chips, however, it appears that TSMC is ramping up to take on a larger role in Apple's plans.