Numonyx CEO defends phase-change memory

He told a somewhat sceptical audience that PCM "will enable the next wave of innovation" in the non-volatile memories, and that the pioneering work Numonyx is doing represents "a disruptive technology that will transform the memories sector."

He suggested PCM will "tick all the right boxes" in relation to performance, power retention, ease of use, write speed and cost compared to DRAMs and other flash memories, and parried suggestions that PCM memories will not scale and that it is not a viable memory technology, even though researchers have been working on it for 40 years.

Many in the industry have voiced concerns about the cost-per bit and whether the technology is scalable or able to meet write-speed requirements, but Harrison stressed: "It is not about cost at this early stage. We are looking at this as mainstream in five to ten years, even though we have been shipping samples to about 40 selected customers since 2008."

The part is a 128Mbit device made in 90nm technology.

Speaking to EE Times after his talk, Harrison added, "We are getting revenues for our efforts, not big revenues, but it is a start." He said the discrete devices being shipped are not for handheld applications or high end servers, often touted as the likely main applications for phase change memories.

He said Numonyx—jointly owned by STMicroelectronics and Intel—is already the leading supplier of NOR flash, and, according to recent reports from iSuppli, is the third largest supplier of non-volatile memories.

Harrison said the company is prototyping a 1Gbit version of the PCM that will be made using a 45nm process.

"There are a lot of people working on PCM, but we and Samsung are the only ones with working devices, and we are the only ones in production.

Samsung said late last month it has started making a 512Mbit phase change DRAM using its 60nm process and suggested it could be embedded in some of its handsets soon. Significantly, Samsung revealed almost three years ago it had prototypes of such a part.

"Ultimately, there will be more than two of us in this space, but for now we are leading the charge," said Harrison, adding the two companies have also collaborated on a package specification for PCMs based on the JEDEC standard interface that will be an implementation of the LPDDR2 interface.

"We have both recognised that there is already a need for a non-proprietary solution for these devices," he noted.

Speaking to EE Times, Harrison said, "We have taken on board some of the elements of the scepticism we are seeing and hearing about PCM, ad some of its is fair, but this is not coming from the designers at some 40 companies that we are working with, and it is their feedback that matters most to us at this stage. I hear the comments about 40 years, but we have definitely taken this technology beyond the concept stage."

- John Walko
EE Times