SK Hynix and Toshiba have both experienced lower-than-expected yield rates for their 3D NAND technologies resulting in fewer supplies for Apple's 2017 series of iPhones, according to industry sources. The overall supply of NAND flash chips for the upcoming iPhones has fallen short of demand for the devices by as much as 30%.

Apple has turned to Samsung for more NAND chip supplies for its upcoming phones, since Samsung has relatively stable yield rates for 3D NAND technology and has scaled up its output of 3D NAND chips, the sources indicated.

Android phone makers are also gearing up to introduce new flagship devices. As many of the major NAND flash suppliers are still seeing disappointing yield rates for their 3D NAND technologies, the global supply of NAND flash chips is set to remain tight through the end of 2017, the sources said.

Samsung, Toshiba and Micron Technology are transitioning to 64-layer 3D NAND flash products, while SK Hynix plans to jump straight to supplying 72-layer 3D chips.