Researchers Show Potential Of NRAM At VLSI 2014 - Printer Friendly version without Comments

Appeared on: Friday, June 13, 2014
Researchers Show Potential Of NRAM At VLSI 2014

Japanese researchers have demonstrated a NRAM, a high-density nonvolatile Random Access Memory that could replace all existing forms of memory, such as DRAM, SRAM and flash memory.

NRAM (carbon nanotube nonvolatile memory) is considerably faster and denser than DRAM, has substantially lower power consumption than DRAM or flash, it is as portable as flash memory, and is also highly resistant to environmental forces (heat, cold, magnetism). And as a nonvolatile chip, it will provide permanent data storage even without power.

A research group of Ken Takeuchi, Professor at the Faculty of Science and Engineering, Chuo University, jointly with Nantero,Inc., investigated optimized programing methods of NRAM, evaluated 140nm single bit NRAM memory, and demonstrated its operation at high speed, low power, large capacity with high reliability.

NRAM operates On/Off switching by touch (low resistance) / detach (high resistance) of carbon nanotubes triggered by voltage/current pulses.

In the proposed method, which is stable against dispersion and fluctuation in the NRAM memory array, the researchers used 140nm-diameter memory cells. They proved that it was possible to write data with a short write pulse of 20ns and a current value lower than 20?A. At the time of replacing data, resistance value changes by more than 10,000%. Therefore, it might be possible to realize a multi-level cell operation like flash memory.

Moreover, the cycling capability (write/erase endurance) of the NRAM reached 1011 cycles, which is an about 10 million times higher reliability than that of flash memory, showing a potential to be used as main memory.

The research team and Nantero are considering reducing the diameter of the NRAM memory cell to about 10nm and testing the operation of a gigabit-class array.

The work, presented at the 2014 Symposia on VLSI Technology and Circuits, which ended June 13, 2014. Although further work is needed with statistical data evaluation before NRAM can be productized as Gigabit level memory devices, the performance and reliability of NRAM shown was excellent enough to demonstrate that NRAM is a viable technology to implement as "universal memory."

NRAM engineering samples have already been shipped to Natero's customers. The NRAM samples are multimegabit arrays that demonstrate production-ready yield, high speeds (20ns SET/RESET), high reliability (>1000 years at 85C and >10 years at 300°C) and extremely low power consumption.