Making New Memories: 22nm eMRAM is Ready to Displace eFlash
By: Martin Mason
GF’s strategy is to deliver highly differentiated, high-added-value solutions for clients in high-growth markets, and a tangible result of that commitment is our 22nm FD-SOI (22FDX®) embedded MRAM non-volatile memory (NVM) technology, which has entered pilot production for several large IoT clients.
The embedded STT-MRAM (spin-transfer torque magnetoresistive RAM) technology, developed in partnership with Everspin Technologies, Inc., is aimed at IoT, general-purpose microcontrollers, automotive, edge AI and other applications where low-power operation and fast, robust, non-volatile code and data storage is a critical requirement.
GF’s eMRAM technology is unique in that it is a robust MRAM solution, having been designed as a high-volume embedded flash (eFlash) replacement. It has passed rigorous real-world production testing, and enables delivery of persistent data retention and endurance at extended temperatures. That is key for microcontroller applications and wireless connected IoT, where embedded memory must retain code and data at high temperatures, including through solder reflow at 260°C during PCB assembly. It also offers erase and (re)write speeds an order of magnitude faster than eFlash (200 nanoseconds vs. 10’s of microseconds), with comparable read speeds, providing a power advantage over eFlash in many applications.
Although it initially makes use of GF’s power-efficient 22FDX process, MRAM is deployed in ‘back-end-of-line’ metallization, which allows for a robust roadmap with planned derivatives on both FDX™ and GF’s FinFET technology. That’s because STT-MRAM as a memory technology allows for process variations which can be used to tune the memory bit cell. Accordingly, we expect to offer two “flavors” of eMRAM: eMRAM-F on 22FDX for code/data storage right now, and eMRAM-S as a working memory to augment SRAM at 1x nodes in the future.
GF is currently running multi-project wafers (MPWs) with 22FDX-based eMRAM-F designs for several clients, and multiple production tape-outs are scheduled in the next three quarters. Custom design services are available from GF and our design partners, and 22FDX eMRAM process design kits are available with macro densities ranging from 4Mb to 32Mb for individual macros. A 48Mb macro is scheduled for release in 4Q19 as well.
Industry is at a Transition Point
What’s driving great interest in alternative embedded NVM technologies at present is the fact that the industry is at a transition point: The 28nm node is possibly the last cost-effective node for eFlash, and the transition to 22nm geometries is making it imperative to find an alternative that is suitable for new and fast-growing low-power applications.
Many new eNVM memory technologies look interesting but aren’t yet production-ready. For example, RRAM (resistive RAM), which stores data by changing the electrical resistance of a dielectric, is the subject of much research and development but its maturity on 2x nm process nodes is limiting its adoption. Likewise adoption for PCM memory is limited by a lack of foundry support below 28nm.
By contrast, eMRAM from GF is an especially compelling and timely solution. Although the technology is complex and has required a significant investment of time and money to develop and deploy, it offers tremendous performance and versatility. In addition to the power benefits gained by combining the power-efficient base FDX silicon-on-insulator process with eMRAM, GF’s FDX process also has industry-leading RF connectivity capabilities, and extensive IP is available from GF. This all enables delivery of a unique high performance, high integration, low power and small size solution, which brings tremendous value to clients.
In fact, GF is on its third generation of MRAM technology with the 22nm eMRAM product, having also produced Everspin’s 256Mb 40nm and 1Gb 28nm standalone MRAM products as part of a joint development effort.
In addition to eMRAM technology, GF also offers clients eFlash and system-in-package flash (SIP Flash) embedded memories, built in a range of technologies from 130nm to 28nm to meet a broad swath of application requirements.
A Successful Strategy
The rollout of 22FDX eMRAM technology truly shows the success of GF’s efforts to intensify investment in areas where we have clear differentiation and where we can add great value for clients.
Martin Mason is Sr. Director of Leading-Edge eNVM at GLOBALFOUNDRIES. Before joining the company, he was at Maxim Integrated Products in Executive Director roles for Core Products and Precision Conversion Solutions, and prior to that, he served in product marketing and design/application engineering positions at Atmel, Actel, Concurrent Logic and GEC Plessey Semiconductors. He is a graduate of University of Newcastle upon Tyne in England.