Toshiba and Samsung both ponder opening new 3D flash fabs

Financially troubled Toshiba is building a new 3D flash fab while Samsung is delaying an expansion of its 3D NAND fab capabilities. With 3D NAND, layers of non-3D, or planar, flash are built atop one another, to increase a flash chip’s capacity without increasing its footprint. As the cost/bit of 3D NAND progresses to …

[Norman Nescio]

Reliability and longevity

3D flash is great as it allows the size of the junctions to be increased which enables more charge to be stored per element - MLC cells can have as few as 100 electrons per cell, and leakage is a fact of life.

So what I would like is an option to buy flash optimised for data retention for near-archival storage. I could accept needing to power the flash up annually to run a data self-refresh, or something like that.

Some relevant links below regarding length of data retention in NAND Flash.

- https://communities.intel.com/thread/13783?start=0&tstart=0

- http://www.eeweb.com/blog/eli_tiomkin/industrial-temperature-and-nand-flash-in-ssd-products

- https://users.ece.cmu.edu/~omutlu/pub/flash-memory-data-retention_hpca15.pdf

- http://ita.ucsd.edu/workshop/14/files/paper/paper_293.pdf

Does anyone have any better info on data retention?

From the eeweb link above, you can see that storing stuff at lower temperatures is 'better'.

[Mark Hahn]

Your explanation of 3d flash is exactly wrong: it's not just layers of planar flash.