‘Holy Grail for Memory Technology’: New Candidate for Universal Memory Emerges in Race to Replace RAM and NAND – and It Doesn’t Use a Toxic Compound
Today’s $165 billion per year memory market is dominated by DRAM and NAND flash. The first is fast and has excellent endurance, but is volatile and requires constant data refresh. The latter, on the other hand, is non-volatile and retains data when not powered, but is slower and has poor program/erase cycling endurance.
ULTRARAM, developed by Quinas Technologya spin-off from Lancaster University in Great Britain, combines the benefits of both to provide fast, non-volatile memory with high endurance and ultra-low switching energies.
The technology, which recently won an award at the Flash Memory Summit, has superior longevity to flash storage, matches system memory read/write speeds and requires less power.
Resonant tunneling
ULTRARAM uses a quantum mechanical process called resonant tunneling, which allows it to deliver non-volatility with fast, low-power write and erase capabilities, leading to high endurance. This combination of qualities was previously considered unattainable, which is why some call it the “holy grail for memory technology”.
ULTRARAM is not silicon-based, but rather uses materials known as III-V compound semiconductors, including gallium antimonide (GaSb), indium arsenide (InAs), and aluminum antimonide (AlSb).
Unlike flash memory, which uses a highly resistive oxide barrier to trap charge, ULTRARAM uses atomically thin layers of InAs/AlSb to create a “triple-barrier resonant-tunneling” (TBRT) charge-confining structure. This allows ULTRARAM to switch between a highly resistive state and a highly conductive state, giving it its unique properties.
The energy efficiency of ULTRARAM is certainly impressive. It has a reported switching energy per unit area that is 100 times lower than DRAM, 1000 times lower than flash and more than 10,000 times lower than other emergent memories. The ultra-low energy properties are further enhanced by the non-destructive read and non-volatility, eliminating the need for renewal.
The staying power of ULTRARAM is also remarkable. Quinas claims it has demonstrated degradation-free operation for more than 10 million program/erase cycles.
The development of ULTRARAM is timely as data centers consume increasing amounts of electricity. By reducing the energy required to keep data alive in active memory or moving it between stored and active memory, ULTRARAM could significantly reduce the industry’s energy needs.
And another advantage? The inventors say it can be mass-produced using existing manufacturing processes in the semiconductor and silicon industries.