@uhrmannt, thanks a lot for explaining the differences between the two technologies...it helps me a lot!
How are the Everspin devices performing in the field? Any idea how reliable they are and any technical advantage the offer compared to traditional semiconductor technology?
Indeed Everspin is on the market with MRAM already for a couple of years. However, their technology is highly different to the STT technology, despite relying on the same tunneling magneto resistance (TMR) effect.
Everspin uses TMR junctions with a size being in the size of couple of hundred nanometers. These mainly elliptical junctions face that problem that their remagnetization/switching field is increasing largely when shrinked down (where the socalled paramagnetic state marks the fundamental limit). This issue of a increasing switching field in combination with their matrix grid switching (a current pulse is applied to a wire grid, where the wires cross the oersted field superposes to a value high enough to switch the cell underneath) introduce the scaling down border of this technology.
For SST the switching is by usage of the spin torque effect. In this case the current density of spin polarized current transversing the tunnel junctions has to be huge in order to reverse or change the magentic state and therefore store the information. Mostly the material issues as well as reliability are stating the issues of this new technology.
Everspin (spin-off of Freescale Semiconductor Inc) already has MRAM chips in their product portfolio for quite some time. The density is upto 16Mb for the 16-bit devices. I don't understand the technologies well, but my guess is that the STT-MRAM is a new technology targeted to scale it down, increase its density enough for it to be capable of replacing the DRAM. If I understand correctly, I feel this manufacturers are desperate to overcome the last few hurdles and lunch these products commercially in not more than 2 years. Any different opinion?
I wonder how long will it take for spin based devices to be used in real products...this will mark a major breakthrough in EE: instead of currents, voltages or charges we will be relying on something quite esoteric as a spin of electron...anyone taking bets how many years to production? Kris