Company Macronix Found a solution to the well - known weakness of Memories Flash - Magnetic evaporation. The meaning is simple: the read-write cycles erode magnetism, as magnetism disappears, so does the isolation between cells זיכרון, And their ability to keep information
Flash memory is erased after 10,000 cycles of writing and reading. But now the engineers of Macronix have found Solution Which will give Flash a new and long life. They offer memory NAND Flash has self-healing ability that will allow it to survive over 100 million cycles.
The development was reported At the 2012 IEEE International Electron Devices conference, And that 100 million cycles may not be the real limit. "We do not know what will be the cause of the new memory failure in the end, because we have not yet been able to get a signal for the end of memory life," says Hanging Lu, deputy project manager for Macronix, located in Cinchu, Taiwan. Checking a billion read-write cycles will take several months, he said.
|memory Flash From Macronix|
Memory cell Flash Looks like a standard CMOS transistor: Source and Drain areas with a silicon channel between them, an insulation layer over the channel, and a gate above it all. The main difference in the new development is a layer of material called a "floating gate" embedded within the insulation layer of the regular gate.
The memory bit is stored in the isolation layer, with electrons being pushed to "dig" through the isolation and get stuck in the floating gate. Deleting the bit requires a way to push the electrons out.
|This is how the change in the planning base appears|
But the read-write cycles abrade the isolation layer, and finally the memory cell fails. To compensate for this weakness in my drives SSD, Engineers were forced to adopt complex patterns to ensure that no area זיכרון Not rewritten too often. Levon would repair the damage, but the consensus was that the entire chip would need to be heated to 250 degrees for hours.
Macronix engineers have found the solution in competing technology, Phase change RAM. In PCRAM, each bit is stored in a material called Chalcogenide glass, which holds both the ability to conduct and the ability to isolate.
The material passes between these two states when it is heated quickly and in a certain way. He says that researchers at Macronix have noticed that when the glass is heated beyond its melting point, a healing effect is created in the PCRAM memory. (This data was reported in IEEE International Reliability Physics Symposium April 2012)
|And a little more detail|
The engineers decided that a similar process might also work with flash memory, so they redesigned it chip memory Flash Which includes built-in heaters that can whiten small groups of cells memory. The new design required quite a few changes. The largest of these was the change of gate electrodes to allow the transfer of current to heat the memory cells. The change, which required additional diodes, required so much space that the crew had to plan architecture New for memory arrays so that everything fits the same volume.
The adjusted structure allows the current to pass through the transistor gate and generate pulses of heat several milliseconds long. The researchers found that temperatures pass through 800 degrees, but the important area was limited to the location close to the gate. The chips could cure themselves by this local incandescent to the point where, even after 100 cycles, the memories continued to hold information properly.
One might think that heating of this kind would waste my life battery On computers Mobile for example). The "refresh" does require quite a bit of energy, he agrees, but the incandescent can be done on a low frequency and one area at a time, when the device is inactive but still connected to the power source. "It will not eliminate your mobile phone battery," Lo claims.
The experimental memory holds another surprise: the heating allowed for rapid erasure, which in the past was not associated with one or the other temperature. "Down the road, this feature may be developed into a 'heat-certain' mode of operation that will allow enhanced action - such as quick erasure - as well as prolong life Memories The Flash, ”he said.
Quick erase may allow flash memories to replace Memories Dynamic (DRAM) The fast memory that is disconnected from the power supply and used for computer working memories today - but it will take a long time for development to get there. "memory Flash Is not memory A random approach, and the architecture would have to be completely different, ”he explains.
|the mother Memories Will the flash live forever?|
He also says that Macronix intends to promote the breakthrough of the flash that knows how to correct itself, but does not give details about when and how. He did agree to tell when the industry memory The flash had to use technology. "We took a serious gamble to try a completely different method. A very high temperature for very short periods of time," he continued. "Then, we realized that the wheel wasn't reinvented here, and we could do it even ten years ago."
The implications of this development are enormous. If this is the use of flash memory drives to experience servers to open bottlenecks and energy savings (energy consumption is significantly lower than that of mechanical drives), and if these Memories With long life and fast performance on phones and tablets that are sold in millions of units each year.
Either way, this is one of the things that when you think about it, you hit your forehead and say "why didn't I think of it (ten years ago)?"
This is what will drive the hard drive industry toward drive-based drives Flash, Or is it just one step on the way? Share your thoughts with comments!