A flashy new era

Toshiba and SanDisk have revealed an 8Gbit NAND flash memory chip fabricated with 70nm process technology that the companies say ushers in 1Gbyte data storage capacity on a single chip.


Toshiba and SanDisk today announced an 8Gbit NAND flash memory chip fabricated with 70nm process technology that ushers in the new era of gigabyte chips: 1Gbyte data storage capacity on a single chip.


The new chip was reported today at the International Solid-State Circuits Conference (ISSCC) 2005 in San Francisco.


According to a statement, the new NAND flash memory utilises multi-level cell (MLC) technology that allows two bits of data to be stored in one memory cell, doubling memory capacity. Innovative circuit design techniques were utilised to improve chip area efficiency resulting in an 8Gbit chip size that is less than five percent larger than the previous generation 4Gbit chip manufactured on a 90nm process.


At 146 millimetres square, the 8Gbit chip has an area density of six billion bits or three billion transistors per square centimetre (20 billion transistors per square inch of silicon).


Performance is said to be maximised by adoption of fast writing circuit techniques, which reduce data write times and support a fast write speed of 6MByte/sec. Read speed of 60MByte/sec, which is 40% faster than previous generation, has been achieved by a combination of burst mode and high read bandwidth.


Toshiba and SanDisk plan to start production of flash memory products based on the new 8Gbit NAND flash memory technology this summer. The companies also plan to commercialise a 16Gbit NAND flash memory IC that stacks two of the 8Gbit NAND flash memories in a single package.



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