Samsung Foundry Forum (SFF) 2023 took place in Tokyo, Japan, on October 17th and in Munich, Germany, on October 19th. SFF is Samsung Foundry’s largest annual event, where Samsung shares its latest technologies, business strategies, and vision with global partners and customers.
Samsung’s eMRAM and MRAM, with both currently at the center of next-generation memory innovations, were a few of the technologies highlighted at SFF in both Munich and Tokyo. Since starting commercial shipment of an eMRAM solution based on the 28-nanometer (nm) Fully Depleted Silicon on Insulator (FD-SOI) process in March 2019, the company has been supplying a flash-type eMRAM solution along with a non-volatile RAM (nvRAM)-type eMRAM that can function as working memory. MRAM is central to Samsung Foundry’s core portfolio, and the extent of its capabilities is discussed in an academic paper Samsung Electronics published on the subject.
Samsung Electronics’ Core MRAM Technology: A Paper Highlighting IEDM
In December 2022, Samsung presented a paper titled, “The World’s Most Energy Efficient MRAM Technology for Non-volatile RAM Applications” at the IEEE International Electron Devices Meeting (IEDM), a prominent micro- and nanoelectronics conference. The paper described nvRAM-oriented product technology based on Samsung’s 28nm and 14nm logic process nodes. As acknowledgment of the outstanding research and groundbreaking results it shared, the submission was selected as a highlight paper in the Memory category at IEDM. With this recognition, Samsung reached a new milestone.
Specifically, the enhanced magnetic tunnel junction (MTJ) stack process technology dramatically lowered the Write Error Rate (WER). The MTJ has also advanced to a 14-nm FinFET process from the previous 28nm node, achieving 33% area scaling. This chip-scale sizing allows more chips to be produced from the same wafer, which results in more net dies. Additionally, it enables a 2.6x faster read cycle time1 and the packaging size has been reduced to 30mm2 at 16Mb, the industry’s smallest commercially available dimensions. This solution provides a near unlimited endurance of more than 1E142 cycles at -25°C. But perhaps the crowning achievement is the best-in-class energy efficiency with an active read and write power consumption of 14mW and 27mW, respectively at 54MB/s bandwidth.
Samsung Electronics’ MRAM Innovation: Improved Switching Efficiency and MTJ Scaling
The aforementioned 2022 paper reports two new major achievements for Samsung Electronics’ eMRAM: improved switching efficiency and MTJ scaling.
Switching efficiency3 is the key metric for eMRAM performance. The graphs below display various measurements related to the WER from MTJ Stacks A to C4. As shown, Stack C suppressed delayed read meta-stable (DRM) WER up to two orders more than Stack A without negatively affecting retention. Additionally, repeated single-bit WER test results on an 8Mb array proved that WER distribution in the chip is 20% lower. Through the application of MTJ stack engineering, it was possible to validate a WER at the single-digit ppb5 level.