Trapped charge memories, primarily NROM, accounted for just 6.1 percent of the $23.7 billion flash memory market in 2006 but this is expected to increase dramatically as SONOS NAND variants such as TANOS and BE-SONOS enter the NAND market. "As floating gate flash technologies encounter scaling challenges beyond the sub-40 nanometer generation, trapped charge and phase change technologies are poised to continue NAND and NOR flash scaling", said Gregory Wong, Vice President of Technology Research at Web-Feet Research (Monterey, Calif.) In floating gate technologies, charge is stored in a polysilicon layer whereas in SONOS-based trapped charge technologies, charge is stored in a nitride layer sandwiched between dielectric materials. Phase change memories store bits by switching a chalcogenide material between amorphous and crystalline states. Currently, the vast majority of trapped charge memories are used as NOR flash for code storage, and accounted for 15.7 percent of the NOR flash market in 2006. This is forecast to reach 28.1 percent by 2012.

An even steeper transition is expected for trapped charge memories in the NAND flash market increasing from less than 1 percent now to 30 percent in 2012. Phase change memories are forecast to capture 5.5 percent of the NOR flash market by 2012.