SanDisk introduces first 3-bit-per-cell NAND flash chip

he 16-gigabit (Gb) x3 NAND flash employs SanDisk’s standard 56 nanometer (nm) flash technology and provides over 20 percent more die per wafer compared to standard NAND Multi-Level Cell (MLC) memory (2-bits-per-cell) on the same technology node. x3 enables higher manufacturing efficiency and lower die cost for the same capital investment. The new x3 flash architecture has been in development for the past two years and employs SanDisk’s most advanced patented design innovations to achieve the same performance and high reliability found in SanDisk’s 2-bits-per-cell chips.

The 3-bits-per-cell technology was co-developed with Toshiba which shares with SanDisk the development and manufacturing of advanced flash memories. At the 2008 International Solid State Circuits Conference (ISSCC), SanDisk and Toshiba are presenting today a technical paper describing the key technology advancements that led to the development of 16Gb 3-bits-per-cell NAND flash memory on 56nm technology with a write performance of 8 megabytes per second (MB/sec).

Dr. Khandker N. Quader, senior vice president of flash memory design and product development at SanDisk, said, “Innovative patented All Bit Line (ABL) architecture with advanced proprietary programming algorithms and multi-level data storage management schemes were used to overcome the challenges of developing a 3-bits-per-cell (x3) NAND flash memory chip without sacrificing performance or reliability, thereby paving the way for widespread use of x3 across many of SanDisk’s product lines. We consider x3 as a major commercial breakthrough for flash memory that will extend Moore’s Law in this and future generations of NAND flash storage.”

SanDisk believes that the introduction of 3-bits-per-cell technology with a write speed comparable to existing MLC memory positions SanDisk well to respond to the growing market demands for higher density flash memory for a wide range of applications and at a significantly lower cost compared to 2-bits-per-cell MLC on the same technology. Advanced systems-level expertise is essential to productize 3-bits-per-cell NAND memory. SanDisk’s systems-level expertise provides a unique competitive advantage to harness the power of x3 NAND memory technology.