IBM has built a prototype storage device with two partners that they claim is 500 times faster than Flash.
It uses less than half the power of Flash memory and can be built in ultra-thin form factors most likely unavailable to Flash. In short, a Flash-killer and potentially the answer for a universal memory type for mobile devices.
Infineon spin-off Qimonda, and flash memory company Macronix will show the device at an IEEE conference in San Francisco this week. It uses a new germanium-antimony (GeSc) semi-conductor alloy in a device with a 3nm by 20nm cross-section — far smaller than today’s flash and one predicted to be achieved in 2015 using Moore’s Law extrapolations of chip component size.
Dr TC Chen, an IBM Research VP, said: “Many expect flash memory to encounter significant scaling limitations in the near future. Today we unveil a new phase-change memory material that has high performance even in an extremely small volume.”
Most Flash memory used today has a “floating gate” charge-storing cell designed not to leak. Flash retains its stored data and requires power only to read, write or erase information. This makes the memory popular in battery-powered portable electronics. Non-volatile data retention would also be a big advantage in general computer applications, but writing data onto Flash memory is thousands of times slower than DRAM or SRAM.
Also, Flash memory cells degrade and become unreliable after being rewritten about 100,000 times. This is not a problem in many consumer uses, but is another show-stopper for using flash in applications that must be frequently rewritten, such as computer main memories or the buffer memories in networks or storage systems. A third concern for Flash’s future is that it may become extremely difficult to keep its current cell design nonvolatile as Moore’s Law shrinks its minimum feature sizes below 45 nanometers.
The IBM/Macronix/Qimonda joint project’s phase-change memory achievement is important because it demonstrates a nonvolatile phase-change material that can switch more than 500 times faster than flash memory, with less than one-half the power consumption, and can do this when scaled down to at least the 22-nanometer node, two chip-processing generations beyond floating-gate flash’s predicted brick wall.
Many other suppliers are working in this area. Samsung has already revealed details of its phase-change RAM (PRAM) switching 30 times faster than flash. Commercial availability is expected in 2008.
Intel and ST Microelectronics are collaborating in the area as well. Elpida aims to start commercial PRAM production by 2010.
Elpida, Samsung and Intel/ST speculate that PRAM is fast enough to replace DRAM in mobile devices. The IBM/Qimoda/Macronix device’s switching speed makes it the fastest PRAM yet reported and backs up the idea of PRAM becoming a universal memory technology for mobile devices.
