Spin Transfer Technologies (STT) was established in 2011 by Allied Minds and New York University to develop and commercialize Spin-Transfer Torque Magnetoresistive Random Access Memory (STT-MRAM) technology to create MRAMs with a much better speed-power-endurance operating point than conventional MRAM technologies. STT has assembled a team of world leaders in magnetics and CMOS memory technologies to develop and commercialize its ST-MRAM solution. The company has built a complete magnetics R&D fab at its Fremont, CA headquarters to accelerate MRAM technology development. This fab enables STT to achieve 10-day cycle times in its development process, with device features as small as 10nm – a significant competitive advantage in an industry where 50-100 fab cycles are required to bring a memory technology to commercial readiness.
The company has also established a world-leading team of MRAM circuit and memory architects, realizing that simultaneously optimizing circuits and magnetics produces better results than optimizing either individually. The company has pioneered significant advances in MRAM circuit designs that enable the industry’s fastest, highest-endurance MRAM memories.
STT will commercialize its technology through two paths: licensing the technology to major foundries and IDMs so that they may include MRAM blocks on their customers’ chips, and by developing and selling stand-alone SRAM and ultimately DRAM memory devices. Target applications for STT’s MRAM technology include storage products, mobile devices, microcontrollers, and a multitude of low-energy semiconductor products for the internet-of-things (IoT) market.
STT has raised a total of $108 million from investors in multiple funding rounds.
MRAM Compared to Conventional Memory Technologies
MRAM is emerging as the leading next-generation memory technology that offers significant benefits over today’s incumbent memory technologies of SRAM, DRAM, and Flash. Non-volatile memories, such as Flash, retain information after power has been turned off, but Flash memory suffers from slow write speed, block-oriented reading, very limited write endurance, and extremely high energy consumption when writing data. High-speed memories, such as DRAM and SRAM, offer much faster read and write performance, but each have their drawbacks: DRAM requires an energy-intensive, time-consuming refresh operation to retain data even when the power is connected, while SRAM uses a very large 6-transistor memory cell and suffers from high current leakage and sensitivity to ionizing radiation when operating. In addition, all of these aging incumbent technologies are hitting limits where it is becoming difficult or impossible to continue shrinking them to more-advanced technology nodes.
MRAM has emerged as the leading next-generation candidate because it offers the potential for the non-volatility of Flash with the performance and the endurance of DRAM – and even SRAM cache memories – without the energy/power problems of all of them. STT has demonstrated that switching magnetic orientations can be accomplished much faster and with much less energy than in conventional spin transfer MRAM approaches.
This discovery has significant implications for the development of spin transfer MRAM devices and products, including ultra-fast switching times, very low switching energy, lower cost, much improved endurance, and greater scalability to smaller dimensions.