Toshiba and SanDisk are recognized technology innovators and market leaders in NAND flash memories—the highly versatile, non-volatile memory that continues to be designed into a diverse range of products, including digital still and video cameras, mobile phones and PDAs. Toshiba, a principal inventor of NAND flash memory, has consistently led the way in promoting advances in chip capacity, while SanDisk is a leader in flash data storage card products and a pioneer in high density flash MLC memory technology.
In the new NAND memory cell structure, the floating gate is completely self-aligned to the active area. This design characteristic supports scaling of the structure for fabrication beyond the 90nm design rule and is expected to provide a distinct advantage over the current NAND memory cell structure, where further scaling below 110 nanometers becomes difficult.
The new memory cell structure is designed to support both 2-Gigabit single-level cells (SLC) with an area per bit of 0.041 micron squared as well as 4-Gigabit multi-level cells (MLC), which effectively will have an area per bit of only 0.0205 micron square. The MLC structure allows each memory cell to carry 2 bits of information, instead of 1 bit, and minimizes interference. The larger capacity and low bit cost of MLC will allow Toshiba and SanDisk to reinforce their market leadership and advance their continuing collaboration in new technologies to meet increasing market demands for flash memory. |