Precessional Spin Current provides faster switching times and better stability of data

November 14, 2017

FREMONT, Calif. – Spin Transfer Technologies, Inc. (STT), a leading developer of high-speed, high-endurance ST-MRAM technology, today announced allowance of a United States patent application for its Precessional Spin Current (PSC) structure for MRAM. The PSC, also known as a “spin polarizer,” reduces MRAM power consumption when writing data while simultaneously improving writing speed. This allowed patent will be a key component of STT’s goal of enabling ST-MRAM to match SRAM and DRAM speeds but with lower costs, lower power consumption, and non-volatile data storage that is a hallmark of ST-MRAM.

Key attributes of the PSC technology, US patent application #14/814,036, and entitled “Precessional Spin Current Structure For MRAM,” include:

  • Compatibility with existing pMTJ (perpendicular Magnetic Tunnel Junction) technologies from STT and others. The PSC is formed during deposition, adds virtually no cost or complexity to the pMTJ stack, and can easily be added to existing pMTJ stacks.
  • STT has seen faster switching times on pMTJ devices down to ~25nm in diameter – which is critical for meeting the needs of the high-density SRAM and DRAM markets.
  • Reduction of write distribution tail by accelerating the onset of spin torque on the free layer.
  • STT has measured a 50 percent improvement in Switching Efficiency when programming the anti-parallel state. Efficiency is the ratio of Delta (a key parameter measuring the retention or stability of the device) and the switching current density. Higher efficiency provides designers with valuable performance options – they can reduce power consumption while maintaining the same retention characteristics, or they can increase retention at the same power consumption.
  • Precessional spin current structure enhances read disturb stability by many orders of magnitude which is essential for high speed SRAM and DRAM applications

“With SRAM rooted deeply in the majority of mobile, computing and industrial applications, we’re seeing the need for an ST-MRAM replacement that is less than one-third the size, doesn’t leak, and is persistent,” said Tom Sparkman, CEO of STT. “We currently have some promising initial data on the benefits PSC brings to ST-MRAM technology, and we expect to see more data over the remainder of the year, helping us accelerate the advancement of ST-MRAM into the SRAM, and eventually DRAM markets, and ultimately being able to offer cheaper, simpler, more competitive technologies.”

About Spin Transfer Technologies

Spin Transfer Technologies, Inc. (STT) is developing ST-MRAM technologies that uniquely combine patented magnetics technologies, circuits and memory architectures to create the industry’s lowest-cost, highest-performance ST-MRAM memories. STT’s disruptive ST-MRAM solutions are ideal replacements for embedded SRAMs as well as future DRAM devices. The company was established by Allied Minds and New York University. For more information, please visit

Media Contact:
Justin Gillespie
The Hoffman Agency
(925) 719-1097