Self-healing flash for infinite life

NAND flash is a wearing resource - like tires on a car - which creates many problems for high duty cycle storage. But a Taiwanese manufacturer demonstrates how to overcome that limit. Will it fly in the marketplace?
Written by Robin Harris, Contributor

In an upcoming paper Macronix engineers show how flash cells can be rebuilt on the go.

Today's Multi Level Cell (MLC) NAND flash is typically specified to handle 10,000 writes - plenty for a phone or a point & shoot camera - but less than storage admins would like. If that limit could be raised - infinite writes would be nice! - flash storage would be more popular in data centers.

Heating flash memory cells has long been known to make them like new. But that's a lot of heat and power - impractical for the mobile devices that drive the NAND flash market.

But Macronix, a Taiwanese manufacturer, is demonstrating a
<blockquote> . . . novel self-healing flash, where a high temperature (>800°C), and short time annealing are generated by a built-in heater. </blockquote>

It takes just a few seconds of heating to return cells to a good state. By heating small groups of cells, they enable power-effective self-healing that over time could rebuild an entire flash chip when the device is connected to a power source.

The Storage Bits take
Macronix says that no commercial self-healing chip is imminent. And there's good economic reasons for that, despite the elegance of their design.

NAND flash markets are dominated by the ferocious cost pressures of high volume consumer products. About 95% of the flash market doesn't care about self-healing flash, so there's no way to justify the extra cost of their solution.

With well-engineered solutions, MLC flash can meet stringent enterprise requirements. The Macronix solution may become viable some day, but it isn't needed today.

Comments welcome, of course.

Does the limited life of MLC flash concern you and, if yes, why?

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