to even smaller sizes, packing more memory into the same space. “Flash is hitting the scaling wall,” says Schmergel. “It’s becoming ever more difficult to scale it and make it smaller. By contrast, scaling NRAM is quite simple.”
Packing in more memory is a matter of inscribing smaller features in the layer of carbon nanotubes deposited on the silicon chip. Schmergel says the technology should work with features down to about 5 nanometers in size. Most flash memory is working with features measuring 65 nanometers, though the industry is trying to move to 45 nanometers.
The NRAM technology is designed to be compatible with the current computer chip manufacturing process. Manufacturers would lay down a thin layer of nanotubes on top of a silicon substrate, then use standard photolithography and chemical etching to inscribe the lines that make up various circuits on the chip. “There’s nothing that the semiconductor fabs haven’t seen before other than the carbon nanotube material,” Schmergel says. The technology has to be compatible with current processes if Nantero wants to gain a foothold in the well-established chipmaking industry, which he admits is an enormous challenge. “That’s why we’ve made all of the effort to make sure our memory could be made in today’s fabs, using only the existing equipment and the existing people.”
Indeed, Nantero doesn’t build any memory itself. It’s licensing its technology to a number of partners, including Hewlett-Packard; ASML, the Netherlands-based maker of chip-making equipment; and BAE, a major international manufacturer of electronic systems for consumers and military customers. The partners are developing the processes for making NRAM chips, and have already produced some test chips. Schmergel says he’ll leave it up to the partners to announce when they’ll have products ready for the market, but that the first should show up within a couple of years. “It’s in the near future,” he says, “unlike most nanotech, which is many years away.”
One possible near-term product might be an NRAM-based solid-state drive for a computer laptop. Solid-state drives are available today, based on flash technology, but they cost more and hold much less data than a standard hard drive.
“Most observers of the laptop industry believe that solid-state drives are going to eventually be a huge segment of the market,” Schmergel says. “Hopefully, we’ll be the ones who will convince you to replace your hard drive with a solid-state drive.”