 In 2009, Toshiba and SanDisk introduced NAND flash chips with QLC technology storing 4-bit per cell and holding a capacity of 64Gbit.Samsung Electronics introduced triple-level cell (TLC) technology storing 3-bit per cell, and began mass-producing NAND chips with TLC technology in 2010.Charge trap flash (CTF) technology was developed during the 1990s to early 2000s.