We wouldn’t be able to define the modern age without the word "data." The amount of data generated worldwide is growing exponentially every year, and the increasing importance of applications such as AI, edge computing, and autonomous driving is accelerating this growth even further. In response, the industry is facing high demand for the development and reliable supply of semiconductor chips that achieve high performance while consuming less power and reducing cost.
In this type of environment, embedded magnetic random access memory (eMRAM) — non-volatile memory that uses magnetic domains and integrated into system semiconductors and processors such as micro controllers and systems-on-chips (SoCs) — is emerging as a next-generation product that can provide optimal performance, reliability, and cost effectiveness.
In our previous tech article, “Developing the ‘Industry’s Most Energy-Efficient’ Next-Generation MRAM,” we evaluated Samsung's technological innovations that enabled MRAMs to achieve high performance, high density, and the highest energy efficiency by improving switching efficiency and miniaturizing Magnetic Tunnel Junction (MTJ) size. We also reviewed Samsung’s plans to expand its eMRAM portfolio in the future. In this article, we will take a deeper look at eMRAM based on the fundamental principles of MRAM.
DRAM and MRAM: What’s the Difference?
DRAM has evolved with a continued decrease in cell size, an increase in integration density, and bandwidth improvement, while pursuing low-power consumption as mobile devices become more common. However, DRAM has its shortcomings as a charge-based memory. It needs to continuously refresh to make up for charges that are lost as time passes, even when it is not in operation, which leads to standby power consumption. Furthermore, as integration density increases, so does interference between memory cells, making it extremely challenging to continue scaling DRAM.
This is where MRAM comes in. This type of memory is based on the change in resistance of the unit cell at the MTJ. Since it stores data using its “spin” instead of charge, it retains information almost indefinitely and does not require standby power. It’s an architecture that reduces the total amount of power consumed by a memory device, resulting in high energy efficiency.
New Progress Based on Advanced MTJ Design
The core of Samsung’s eMRAM breakthrough is its enhanced MTJ stack process technology. The MTJ comprises a three-layer structure with an insulating film used as a tunnel barrier between two ferromagnetic1 layers. One ferromagnetic layer is “free” and can have its magnetization direction easily adjusted, while the other is “pinned” with a fixed magnetization direction.