The evolutionary path for DRAM and NAND flash technologies

Article By : Majeed Ahmad

The Korean memory chipmaker highlights the evolutionary path for DRAM and NAND flash technologies in a keynote address to IEEE IRPS.

Technology and trade media has been buzzing about the next-generation memory technologies, but what about improvements in the entrenched DRAM and flash technologies? SK hynix CEO Seok-Hee Lee has outlined the evolutionary path for DRAM and flash memory technologies in his keynote address to the IEEE International Reliability Physics Symposium (IRPS).

For DRAM, Lee mentioned overcoming patterning limitations, maintaining cell capacitor capacitance, and securing technology for low-wiring resistance as the key measures. SK hynix has been employing extreme ultraviolet (EUV) lithography to overcome the limitation of patterning. Next, to maintain cell capacitance (Cs), the company is developing new materials with high dielectric constant while trying to refine the dielectric thickness and innovate the cell structure.

Finally, to secure wiring technology for low resistance, the memory chipmaker is developing next-generation electrode and insulating materials while introducing new processes. Moreover, for applications like automotive, which mandate high reliability in DRAMs, SK hynix is applying optimized process technology to increase the tolerance to soft errors.

illustration providing details of Innovations in materials and structuresFigure 1 Innovations in materials and structures are at the heart of the evolution of DRAM and NAND flash technologies. Source: SK hynix

Likewise, for flash memory, Lee outlined the major venues for improvement. That includes developing high aspect ratio contact (HARC) etching technology, securing cell dielectric properties, and addressing film stress. SK hynix is employing etching technology to implement high aspect ratio (A/R) and thus realize the high-density flash memory devices.

The memory chipmaker is also introducing the atomic layer deposition (ALD) technology to further improve the cell property for efficiently storing electric charges and exporting them when needed. At the same, it’s developing technology to maintain uniform electric charges through innovative dielectric materials. Finally, to address film stress, SK hynix is trying to manage the level of mechanical stress applied to films while the company is attempting to optimize the cell oxide-nitride (ON) material.

Memory’s role in energy, climate initiatives

The theme of Lee’s keynote was “Memory’s Journey towards the Future Information & Communications Technology World.” He linked the improvements in memory semiconductors to energy efficiency as well as a boost in compute performance.

illustration showing how Memory technology innovations will influence climate initiativesFigure 2 Memory technology innovations are crucial in low-power computing, which in turn, will play a critical role in energy and climate initiatives. Source: SK hynix

Lee quoted the data center example, which can operate from a small room with high-speed computation and storage, and thus save thousands of square meters as well as conserve a vast amount of power. He noted that if the hard disk drive (HDD)-based data storage system is replaced with low-power solid-state drives (SSDs) in data centers worldwide, greenhouse gas emissions can be reduced by approximately 41 million tons.

That, in turn, can create social values worth more than $3.8 billion, making improvements in the existing memory technologies imperative for energy storage and climate change initiatives. The improvements in DRAM and flash semiconductors will also be crucial in the next-generation 5G, autonomous vehicles, and artificial intelligence (AI) applications that are increasingly generating and consuming data in near real-time.

“We are improving materials and design structures for technical evolution of DRAM and NAND flash,” Lee concluded. “With these improvements, it’s possible to achieve the DRAM process below 10 nm and stack over 600 layers of NAND in the future.”

Watch the keynote address below:

This article was originally published on EDN.

Majeed Ahmad, Editor-in-Chief of EDN, has covered the electronics design industry for more than two decades.

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