MRAM pioneer moves to 20nm, preps sampling program

September 27, 2016 // By Peter Clarke
Spin Transfer Technologies Inc. (Fremont Calif.), a developer of MRAM technology, has announced it has developed magnetic tunnel junctions down to 20nm in width and has initiated a sampling program.

Spin Transfer Technologies (STT) is a subsidiary of Allied Minds LLC, essentially the method by which Allied Minds acts as an investor in the startup. Barry Hoberman, CEO of STT, told eeNews Europe that the use of a back-end of line (BEOL) R&D fab built by the company at its base in California has been key to getting a series of devices made and characterized in a timely manner.

STT has been pioneering something called orthogonal spin transfer (OST) MRAM in which the magnetic fields of the pinned and variable magnetic layers are perpendicular to the plane of the surface of the wafer. One of STT's developments is to put an additional spin polarizing filter above the variable magnetic field layer.

An additional spin polarization filter and propritary write and read circuitry contribute to claimed advantages for OST-MRAM. Source: Spin Transfer Technologies.

The R&D fab has allowed the company to compress engineering development cycles to 10 days that otherwise would have taken several months, said Hoberman, CEO of STT. “In just four years, STT has taken the journey from incubation to commercialization. We are excited to enter the next phase of the company’s evolution," he said in a statement.

MRAM is also being investigated elsewhere and is now being tipped as the prime embedded non-volatile memory option at 28nm (see MRAM is leading embedded NVM race, says IMEC researcher and Globalfoundries offers embedded MRAM on 22nm FDSOI ).

ST-MRAM beats DRAM, SRAM for cache in many applications and is superior to embedded flash at 28nm and below where it demonstrates 1000x lower write energy and can be implemented in BEOL for easy integration with analog, high-voltage and RF. Resistive RAM (ReRAM) alternatives have yet to demonstrate reliability.

Since 2012 STT has raised $106 million in venture capital – $36 million early in 2012 and $70 million in October 2014.

Hoberman said STT's business model is two-fold; to be a fabless