Notizie

IEDM: fastest STT-MRAM for embedded storage

It is aimed at embedded memory, such as for cache in IoT and AI applications.

“This is currently the world’s fastest write speed for embedded memory application with a density over 100Mbit and will pave the way for the mass-production of large capacity STT-MRAM,” according to the University. “The current capacity of STT-MRAM is ranged between 8Mbit and 40Mbit.”

STT-MRAM is non-volatile – it retains data even with power removed – leading to it gaining traction as the next-generation technology for embedded memory, main memory and logic, said Tohoku. “Three large semiconductor fabrication plants have announced that risk mass-production will begin,” it said.

The team, from the Center for Innovative Integrated Electronic Systems (CIES) used magnetic tunnel junctions (MTJs) integrated with CMOS.

To reduce the memory size , the MTJs were formed directly on via holes.

In the fabricated chip, sub-array write speed was measured at 14ns at 1.2V. “To date, this is the fastest write speed operation in an STT-MRAM chip with a density over 100Mb in the world,” claimed the Center.

IEDM paper: ’14ns write speed 128Mb density embedded STT-MRAM with endurance >1010 and 10yrs retention @ 85°C using novel low damage MTJ integration process’.

Image:
Left, artists impression of 128Mbit-density STT-MRAM
Right, Shmoo plot for write speed versus supply voltage, which shows the measured bit rate at each speed and voltage.