STT-MRAM

STT-MRAM (also called STT-RAM or sometimes ST-MRAM and ST-RAM) is an advanced type of MRAM devices. STT-MRAM enables higher densities, low power consumption and reduced cost compared to regular (so-called Toggle MRAM) devices. The main advantage of STT-MRAM over Toggle MRAM is the ability to scale the STT-MRAM chips to achieve higher densities at a lower cost.

STT-MRAM has the potential to become a leading storage technology as it is a high-performance memory (can challenge DRAM and SRAM) that can scale well below 10nm and challenge the low cost of flash memory.

What is STT-MRAM?

STT stands for Spin-Transfer Torque. In an STT-MRAM device, the spin of the electrons is flipped using a spin-polarized current. This effect is achieved in a magnetic tunnel junction (MTJ) or a spin-valve, and STT-MRAM devices use STT tunnel junctions (STT-MTJ). A spin-polarized current is created by passing a current though a thin magnetic layer. This current is then directed into a thinner magnetic layer which transfers the angular momentum to the thin layer which changes its spin.

What is perpendicular STT-MRAM?

A "regular" STT-MRAM structure (similar to the one you see above) uses an in-plane MTJ (iMTJ). Some STT-MRAM devices use a more optimized structure called perpendicular MTJ (pMTJ) in which the magnetic moments are perpendicular to the silicon substrate surface.

Perpendicular STT-MRAM is more scalable compared to iMTJ STT-MRAM and is also more cost competitive. Perpendicular STT-MRAM is thus a more promising technology to replace DRAM and other memory technologies

STT-MRAM chips

Several companies, including IBM and Samsung, Everspin, Avalanche Technologies, Spin Transfer Technologies and Crocus are developing STT-MRAM chips. In April 2016 Everspin announced that it started shipping 256Mb ST-MRAM samples to customers. The new chips demonstrate interface speeds comparable to DRAM, with DDR3 and DDR4 interfaces. Volume production is expected "soon".

In August 2016 Everspin started sampling pMTJ-based ST-MRAM chips. The first chips are also 256Mb in size, but the pMTJ versions offer improved performance, higher endurance, lower power, and better scalability compared to previous iMTJ ST-MRAM products. Everspin is now ramping out 256Mb pMTJ ST-MRAM production and is developing a scaled-down 1Gb version.

 

 

Latest STT-MRAM news

Hprobe releases a new MRAM testing module to help increase production yields

Hprobe, a developer of testing equipment for magnetic devices, announced a new addition to its product line, the RF Pulse Module. The company says that this is the first commercially available testing system to both collect statistics of error rate of the memory unit cell and take a deep look into switching dynamics of resistive memories.

Hprobe IBEX WAT H3DM Light photo

Hprobe's IBEX system

Hprobe says that the RF Pulse Module is two orders of magnitude faster than existing devices and can help increase manufacturing yields. Hprobe has already begun shipping to tier-1 companies and major research institutes around the world.

Read the full story Posted: Dec 03,2022

Hprobe releases a new MRAM testing module to help increase production yields

Hprobe, a developer of testing equipment for magnetic devices, announced a new addition to its product line, the RF Pulse Module. The company says that this is the commercially available testing system to both collect statistics of error rate of the memory unit cell and take a deep look into switching dynamics of resistive memories.

Hprobe IBEX WAT H3DM Light photo

Hprobe's IBEX system

Hprobe says that the RF Pulse Module is two orders of magnitude faster than existing devices and can help increase manufacturing yields. Hprobe has already begun shipping to tier-1 companies and major research institutes around the world.

Read the full story Posted: Dec 03,2022

Everspin to build a new MRAM production line in Indiana, hopes to secuire government support

Earlier this year, Everspin Technologies announced that it aims to build a new production line in the state of Indiana, US, that will increase Everspin's production capacity for both Toggle MRAM and STT-MRAM. The company is working with state and federal government sources to secure funding for the new production line.

Everspin chip render

Everspin says it also plans to work with the local research community to enhance domestic research for MRAM technology development, creating a Technology Development Center at the proposed Indiana-based location. Everspin says that it is the only US-based commercial manufacturer of MRAM devices today, and increasing its capacity in the US is of strategic importance to its commercial and US Government partners.

Read the full story Posted: Nov 22,2022

Everspin reported its financial results for Q3 2022

Everspin Technologies announced reported its financial results for Q3 2022, with revenues of $15.2 million (close to the end of its guidance, and up 3% from last year) and a net income of $1.9 million.

Everspin Technologies chip photo

Everspin says that its product backlog remains strong, but customer inventory adjustments will have an impact on the backlog in coming quarters. The company continues to relieve its supply chain constraints, which is helping to address its unfulfilled toggle MRAM demand.

Read the full story Posted: Nov 10,2022

Everspin's latest EMxxLX STT-MRAM devices are commercially available

Earlier this year, Everspin Technologies announced its latest STT-MRAM devices, the EMxxLX xSPI serial interface memory. The company now announced that the EMxxLX devices are now commercially available.

The EMxxLX family is the only memory device offering density up to 64Mb, octal interface with 400MB/s bandwidth, and compatibility with the xSPI standard. The EMxxLX features 1000X faster write times compared to NOR flash.

Disclosure: the author of this post holds shares at Everspin

Read the full story Posted: Nov 02,2022

Avalanche Technology announced production of its 3rd-Gen 22nm MRAM devices

pMTJ STT-MRAM developer Avalanche Technology announced that its latest 3rd-Gen MRAM devices are now in production at its foundry partner, United Microelectronics Corporation (UMC). The company says that its new MRAM chips offer significant density, endurance, reliability and power benefits over existing non-volatile solutions.

Avalanche Technology SPnvSRAM G2 MRAM evaluation board photo

Avalanche's new Parallel x 32 series is offered as a standard product in various density options and has asynchronous SRAM-compatible read/write timings. Avalanche also says that it will soon start developing 16Gb MRAM chips.

Read the full story Posted: Sep 15,2022

Everspin reported its financial results for Q2 2022

Everspin Technologies announced its financial results for Q2 2022, with revenues of $14.71 million (up 24% from Q2 2021) and a net profit of $1.7 million . The company's had a positive cash flow of $4.3 million (up from a negative cash flow of $600,000 last year). At the end of the quarter Everspin had $23.1 million in cash and equivalents.

Everspin 1Gb STT-MRAM chip photo

Everspin expects that industry supply constraints will limit supply, and the company reduces its forecast for Q3 2022 - with revenues seen to be in the range of $14.4 million to $15.4 million. Everspin says that price increases from its suppliers and expenses related to 28nm STT-MRAM development will reduce its earnings next quarter and the company will be breakeven or with a small profit.

Read the full story Posted: Aug 12,2022

Everspin announces a new 128Mbit xSPI STT-MRAM product

A few months ago, Everspin Technologies launched a new family of SPI/QSPI/xSPI interface MRAM products that offer the world's highest performance persistent memory with full read and write bandwidth of 400 Megabytes per second through the new JEDEC expanded Serial Peripheral Interface (xSPI) standard interface. The EMxxLX family was launched with densities ranging from 8 Mbit to 64 Mbit.

Everspin Technologies chip photo

Today Everspin announced a new xSPI MRAM device, the EM128LX, that expands the product line to 128Mbit.  Everspin says that the combination of increased density with up to 233 megabytes/second full read and write bandwidth means that system designers now have the option of merging code and data memory on the same device, reducing cost, power, and area.

Read the full story Posted: Aug 02,2022

ITRI joins forces with TSMC and NYCU to develop next-gen MRAM technologies

Taiwan's Industrial Technology Research Institute (ITRI) announced two new MRAM collaborations. The first one is with Taiwan's TSMC, for the development of SOT-MRAM array chips. The second collaboration is with National Yang Ming Chiao Tung University (NYCU) to develop magnetic memory technology that can perform across a wide operating temperature range of nearly 400 degrees Celsius.

Together with TSMC, ITRI is developing low-voltage and current SOT-MRAM, that features high write efficiecny and low write voltage. ITRI says that its SOT-MRAM achieves a writing speed of 0.4 nanoseconds and a high endurance of 7 trillion reads and writes. The memory also offers a data storage lifespan of over 10 years.

Read the full story Posted: Jun 28,2022

Renesas develops 22-nm circuit technologies for embedded STT-MRAM

Renesas announced that it has developed 22-nm embedded STT-MRAM circuit technologies. Renesas developed a test 32-megabit (Mbit) chip with an embedded MRAM memory cell array that achieves 5.9-nanosecond (ns) random read access at a maximum junction temperature of 150°C, and a write throughput of 5.8-megabyte-per-second (MB/s).

To achieve this performance, Renesas developed two technologies. The first is a fast read technology employing high-precision sense amplifier circuit, utilizing capacitive coupling. The second is a fast write technology, with simultaneous write bit number optimization and shortened mode transition time.

Read the full story Posted: Jun 18,2022