Unity's New CMOx Memory Technology Appears on Horizon

Summary: Unity Semiconductor has come forth recently with a new candidate for Storage Class Memory technology, CMOx, which uses metal oxides as the data storage medium, and changing the presence of those oxides by application of an electric field. CMOx looks promising, cost-competitive with the roadmap potentials for existing silicon NVMs, high-enough performance, and scalable to under 20nm. But we are still two years from seeing something close to first production material, at densities and possible costs that will enable us to really check the early returns and expectations, against realities. For now, we can only stay tuned.

The Company: Unity has 42 employees, with a wide range of semiconductor pedigrees from Inmos, Micron, Fairchild, Ramtron, Simtek, and AMD. It is headed by Darrell Rinerson, formerly an Executive at Micron Technology, who with two others founded the company in 2002. Darrell is the lead patent developer listed on most of the patent plaques lining the entry hall of the companies' Sunnyvale facility.

Now seven years old in development, and with a total of $75M in three rounds of funding, Unity is confident enough in its technology and roadmap to start talking to manufacturing partners, as it concurrently moves product and technology development from 'proof of concept' to 'characterization' and something close to 'production-readiness' over the next two years.

Should this technology pan out in a way close to what early analyses and tests have indicated is possible, at equivalent process nodes, CMOx can be expected to have 4x the density of NAND flash, 5x the write speed of NAND, and require little in the way of special processing flows. Compared to MLC NAND's 2F2 cell size, CMOx's is merely 0.5F2, and it has no transistor to limit extreme scaling. Though still two years away from production-readiness' CMOx memories are being positioned as something of 'The Mother of All Storage Class Memories' that are taking aim at sockets where conventional silicon cannot reach for price or performance reasons. Conceivably, CMOx could even replace HDDs, and expand markets into heretofore unidentified markets, applications and products.

These are 'Great Expectations', to be sure, and a long road to travel between today's 64Mb test vehicle, now undergoing characterization in Unity's labs, and its 64Gb device, scheduled to be available in 1H11.

Novel manufacturing process flow: With the Unity CMOx storage cell technology innovation, other important business and manufacturing decisions can change. For one, for the first several masking layers, Unity's wafers can effectively use a standard bulk CMOS process, at a back generation process node, for the FEOL. They can buy common 90nm processes wafers for their CMOx memory feedstock. These 'pre-uncommitted memory arrays' are then transferred to a more state-of-the-art BEOL, for the metal oxide and metal layers, and deposition and building of the actual storage features.

'Go to market'...how, exactly? Furthermore, in the midst of today's memory meltdown, Unity is very interested in its own go-to-market model, and intent on devising a method of taking its product to market without creating the overly-commoditized bloodbath we have seen for more than a year in DRAMs and NAND flash. For this, their 'plan of record' today is to join forces with an existing memory manufacturing partner, and have limited production sufficient to service that market that can use the superior performance of CMOx (at a price, to be sure). Of course, they will have to weigh carefully the option of reducing prices and broadening the market...but this decision will have to wait until the product itself is fully characterized and the existing and potential 'high value niches' better understood.

Unity is convinced that broad licensing of CMOx would collapse the market into a food-fight, and leave everyone with nothing, as it has, periodically, for traditional DRAM and NAND flash licensing programs almost since the industry's inception.

Licensing, adoption, production: evidence and options:
To add some perspective to this problem, specifically that of the owner of a potentially valuable "Memory IP", it is worthwhile to see other ways of 'going to market'. These days, Pure IP Developers are denigrated in some quarters as being 'patent trolls', leaches and worse. They 'make' nothing, and are viewed as riding on the backs of those who do make products. Historically, IP developers made products that demonstrated the value of their IP, and got paid in product profits. Sometimes 'secret sauce' of proprietary but undisclosed and unpatented technolgies, remained out of view for years from competitors. But, especially among the industry's early founders, broad cross-licensing took place, and no one was denied access to any other technical developments in their field, though license and royalties flowed continuously. That started to change in the mid-1980s with a huge TI patent offensive against DRAM makers, and was turned on its head entirely with the founding of Rambus in 1990s, who was the first pure-play IP company in the industry.

The conundrum is that however much the IP costs, the cost use it in a DRAM/memory/semiconductor product, and take it to market, is far greater, with today's $3B memory fabs and established channels to customers. A standalone IP developer has to find a manufacturing partner to bring his ideas to life in the marketplace, and to profitabliity. And, even if one has an allegedly superior capability, it is no guarantee of a big money stream, and there is never any guarantee that it is 'forever.'.

Rambus DRAMs have demonstrated superior performance to standard DDR1-2-3 for more than a decade now, but have not enjoyed significant take-up in the market, and have thrust Rambus themselves into a never-ending sea of lawsuits...which pariah status Unity seeks to avoid.

There are, of course, instances of sustained significant technical leadership and profitability from time to time in the semiconductor memory business, but, as all the players have the same basic tool box (or, sandbox, since its silicon), eventually Intel loses its HS 1K and 4K SRAM monopoly to Hitachi, Inmos and AMD; Samsung loses its 8M WRAM monopoly to DDR1 and wide IO, Standard G DRAMs and IBM loses its UHS SRAM sales leverage with customers Sun and HP, (sustained at $140/8M unit for years) to Samsung, and then GSI (though other factors were at work there, too.) System manufacturers are highly adept at working around costly components in their systems (see "History of RL DRAM"), as are the thousands of engineers working on new materials and methods at working around what appear to be an insurmountable patent position. Wang Labs x9 SIMM patents, earning them a cool $90M in the early '90s, became worthless with the onset of x32/x36 DIMMs. CDMA technology from Qualcomm is a non-memory example, with which they have generated a significant monopoly profit stream AND widespread adoption for many years, though not without a battle at every juncture.

Rambus, Wang Labs and sometimes Qualcomm (and formerly, TI) have engendered some intense bad feelings in the industry by the way they 'exploited' their IP...which they feel is just getting paid for their technical contributions, "and if you don't like it...'

Balancing what some would call 'IP greed' with market needs and 'ability to pay' is a hard act to manage, as we have seen many times. Broad licensing and cross licensing of IP has been the common industry practice since its earliest days; good for the consumer, but maybe not for the IP holders or other intermediaries, who cannot differentiate their products.

Unity's manufacturing partnership plan is their way of limiting access to their technology, bringing production only to a level of a manageable market presence that shows good profitability in those applications that can appreciate CMOx unique capabilities. Once the show hits the road in 2011, we will see how well this works. (Saifun faced a similar quandary when they developed NROM technology...be an IP company or build a fab? This was discussed in an early DMR article.).

The Challenges Ahead: This looks like a promising technology worth watching. Only more time and more development and characterizations, and more critical evaluation in real-life applications, will tell us if CMOx is as good as it now looks. Many other technologies looked good for a while, but ran into cost, scalability, or performance challenges that could not be successfully overcome. MRAM was all the talk 3-4 years ago, but has given way to Phase Change Memories (PCMs) today as the most talked-about heir apparent to the extensible silicon roadmap on scaled NAND flash. With technical roots, and claims of Universal Memory Domination dating back at least to the early 1980s, Numonyx informs us in a press release from last December that they shipped the industry's first PCM memory for revenue in 4Q08.

In addition, the Status Quo is not standing still; silicon NAND marches on, downward in cost, towards and beyond 30nm processing by the time the first CMOx 64Gb device is shipped in 2011.

But if these claims come anywhere close to standing up under two more years of development and scrutiny, CMOx's domain will extend far beyond where we see silicon NVMs applied today...'cheaper and faster' is a hard to beat combination.