'Universal memory' race still on the starting block

'Universal memory' race still on the starting block
SAN FRANCISCO -- A slew of promising ''universal memory'' technologies were disclosed at this week's International Electron Devices Meeting (IEDM) here, but don't look for mass adoption anytime soon.

At the same time, Everspin, Hynix, Infineon, IBM, Micron, Numonyx, Renesas, Samsung, Spansion, Toshiba and others are placing huge bets on one of the many candidates in what could be a ''winner take all'' game in the ''universal memory'' sweepstakes.

But economic factors, coupled with a possible slowdown in IC scaling, could once again push out the mass adoption of these ''universal' candidates, such as FRAM, MRAM, phase-change memory (PCM), programmable metallization cell (PMC), resistive RAM (RRAM) and others. "Universal memory'' implies the ability to combine the capacity and cost benefits of DRAM, the fast read and write performance of SRAM, and the non-volatility of flash.

Some thought that many of these technologies would hit mass production or the mainstream by 2011-to-2013--or before. At that time, leading-edge flash devices are expected to hit the wall at the 22-nm node or so.

Beyond that, it could be a huge challenge to scale. The floating-gate structure is the key component of today's NOR and NAND devices, but many wonder just how long the technology will scale before running out of gas. And in DRAMs, the capacitor is close to hitting the wall, prompting the need for a new technology.

Clearly, there are signs that memory scaling could slow down, as vendors are hitting a number of roadblocks in process and design technology. ''22-nm will be delayed or pushed out,'' said Alan Niebel, chief executive of Web-Feet Research Inc. (Monterey, Calif.).

In other words, current memory technologies may live longer than expected. This in turn could slow or push out the mass adoption of universal memory types, he said.

Winners, losers

So right now, there are no clear winners or losers in the ''universal memory'' sweepstakes. Some memory types have shipped in limited volumes. Others are still waiting on the runway, leaving skeptical customers to wade through the hype.

Every year, some vendors declare that their respective ''universal memory'' products will become mainstream. But every year, most--if not all--of these products fail to live up to the hype, and, in some cases, are delayed for one reason or another.

Some say that ''universal memory'' will gain traction from 2011 to 2014. It's a moving target, but it could come down to economics, Niebel said. The eventual winner in the ''universal memory'' sweepstakes will depend on which technology will obtain the most funding, he said.

But over time, it has become painfully clear that the term ''universal memory'' is a misnomer. It's simply difficult to develop a true ''universal memory'' that can combine the attributes of DRAM and flash, he said.

As a result, the prospective products will perform some but not all functions. ''Eventually, I don't think you will call them universal memories,'' he said. ''They will be niches.''

So which technology has the lead now? Phase-change has a slight lead, while RRAM is gaining interest, he said. ''The MRAM guys will find a niche, but I'm not holding my breath,'' he added.

''PCM is closest to commercialization and by end of next year it could be competitive with NOR flash, but it'll take another few years to really get traction,'' said Gregory Wong, an analyst with Forward Insights (North York, Ontario, Canada).

''Everyone's focusing on spin-torque (STT) MRAM, but the cell sizes are still too large. It could be interesting as an embedded memory, replacing RAM and flash on a die,'' Wong said. ''RRAM is also in the early stages but companies are taking a close look at this because if you can get it into a cross-point array, with MLC or stacking cells, it could potentially replace NAND.''

Like the analyst from Web-Feet, Wong believes that next-generation memory technology will perform some but not all memory functions. For example, PCM is geared for code and code/data storage, SST-MRAM is aimed for embedded memory, and RRAM for data storage.

''As for emerging memories, I think the economic situation will force companies to look very carefully at their R&D portfolio and continue to place bets on only those technologies which have the best commercialization potential instead of taking the shotgun approach,'' he added.