Fujitsu is licensee of Nantero's carbon-nanotube RAM

August 31, 2016 // By Peter Clarke
Fabless chip company Fujitsu Semiconductor and foundry Mie Fujitsu Semiconductor have both announced that they are licensees of carbon-nanotube non-volatile memory technology from Nantero Inc. (Woburn, Mass.).

Nantero was founded in 2001 and has spent 15 years developing its technology, which it claims offers the potential to become a non-volatile replacement for DRAM. It also offers rewrite speeds and endurances thousands of times higher than those of NAND flash memory.

Nantero has been pursuing an intellectual property licensing business model for some time and has been claiming that its technology has been installed in numerous wafer fabs and foundries but until now has not revealed any licensees.

Greg Schmergel, Nantero's CEO and co-founder, told EE Times Europe that the Fujitsu licenses are at the 55nm node with the 40nm node set to follow. He added that Nantero is working with other partners at the 2X-nm node. Shmergel said that Nantero has more than 12 customers in place for its CNT memory technology including "several of the top ten users of memory globally."

Fujitsu Semiconductor plans to develop a custom chip with embedded NRAM by the end of 2018, with the goal of expanding the product line-up into stand-alone NRAM components. Mie Fujitsu Semiconductor, which is a pure-play foundry, plans to offer NRAM-based technology to its foundry customers.

Nantero is also supporting design work on a multigigabyte DDR4 stand-alone memory, Schmergel said. The capacity of the design and any component is not yet final but will be four to eight layers and between 8 and 32Gbits, Schmergel said. "However, we think Fujitsu could be the first to get products out in 2018," he added.

The principle of operation of the nanotube memory is a layer of carbon nanotubes (CNTs) in a random mesh matrix structure with hundreds of CNTs per device with many different intersection points, embedded within a conventional CMOS process. The number of CNTs that make contact and the effective resistance across the layer is dependent upon an applied voltage and can be set and reset.

The resulting memory offers memory cell switching speeds of the order of 20-picoseconds at low-energy together with a practical write speed of 5ns with endurance of the order of 10^11 cycles. This holds out the prospect that CNT-based NRAM can be superior to competitor technologies such as ReRAM and phase-change memory and scale better in geometry to become a universal memory to replace both DRAM and NAND flash memory.

Next: NRAM to follow FRAM