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"Self-Healing" NAND Flash Memory That Can Survive Over 100 Million Cycles

Posted by Unknown on from the forged-in-the-fires-of-mount-nand dept.

another random user writes with an interesting use of 800C heating elements to keep flash working longer. It's long been known that heating NAND to temperatures around 250C can restore life, but doing so was practically impossible. From the article: "Engineers at Macronix have a solution that moves flash memory over to a new life. ... They redesigned a flash memory chip to include onboard heaters to anneal small groups of memory cells. Applying a brief jolt of heat to a very restricted area within the chip (800 degrees C) returns the cell to a 'good' state. ... According to project member HangTing Lue, the annealing can be done infrequently and on one sector at a time while the device is inactive but still connected to the power source. It would not drain a cellphone battery, he added." It's still a long way from commercialization, but if it works on a small scale...

6 of 76 comments (clear)

  1. Re:800C? by space+fountain · · Score: 5, Interesting

    Probably not enough power.

  2. Re:800C? by mfwitten · · Score: 5, Informative

    As you later hint, a high temperature does not imply a great deal of heat. Also, a hardware fail-safe (i.e., a fuse) is the obvious solution to any such maliciousness.

  3. Re:800C? by Anonymous Coward · · Score: 5, Informative

    You do realize that Incandescent light bulbs are at 3000K or so. So, they have been letting things get over 800C since the beginning of commercial airlines.

  4. Re:800C? by hamjudo · · Score: 5, Insightful

    The very, very small area is probably a few orders of magnitude smaller than your concept of very very small. The ieee article says it will take months to test 1 billion cycles. There are on the order of 10 million seconds in 4 months, which means the researcher thinks he can test at the rate of 100 cycles per second. In other words, the regions are so small, it takes on the order of 10ms to cool enough for the next test cycle.

  5. Re:800C? by timeOday · · Score: 5, Informative
    To prevent uncontrolled energy dissipation you can use a fuse.

    Fun fact: the spark plug in your car creates a temperature of 60,000 K (a little over 107,000 F). A cheap 4" (100 mm) magnifying glass can generate a temperature of over 600C. So, like you said, it's all about duration and area.

  6. High temp but low energy by Yarhj · · Score: 5, Informative

    This story has popped up a few places already, and 90% of the comments are always "800C! But what if it catches fire?"

    Yes, the floating gate is heated to 800C, but the volume of the heated area is on the order of a few hundred cubic nanometers. The energy involved in heating a volume that small is, well, incredibly small, and dissipates rapidly into rest of the chip. Your flash memory will not burst into flame. It will not require significantly more energy from your battery, and it will not require special clearance from the TSA to bring it on a plane.

    The real challenge here is not coping with high temperatures, but rather balancing the increase in cell lifetime with the increase in die size. If the 100 million cycles number is completely accurate, then there's not much question that this technology will make its way into a lot of flash, but if that upside is only for a few (or even most) of the bits on a die, then things get more complicated

    For more info run through the comments from the Ars Technica writeup of the same story: http://arstechnica.com/science/2012/11/nand-flash-gets-baked-lives-longer/