4DS (Fremont, Calif.), a subsidiary of an Australian company called 4D-S Pty. Ltd., has also garnered a new round of funding and is now looking for manufacturing partners to commercialize its RRAM technology. The startup is not giving a paper at this week's International Solid-State Circuits Conference (ISSCC), but it appears to want to crash the party.

For years, chip makers have been talking about the development of RRAM, a non-volatile memory and potential ''universal memory'' that combines the density of flash memory and the speed of DRAM. But to date, RRAM technology has been stymied due to material and manufacturing challenges.

A number of companies in Europe, Japan, Korea and the U.S. are scrambling to develop RRAMs. 4DS claims to have beaten its rivals to the punch, by demonstrating RRAM cells and a process within its small-scale fab in Fremont.

The company is now looking for a manufacturing partner to bring its so-called ''4DS memory'' into mass production, said Kurt Pfluger, chief executive of 4DS. "It's a simple process,'' Pfluger said. ''This has the potential to replace DRAMs and flash.''

FRAM, MRAM, phase-change, RRAM and other technologies are vying for dominance in the ''universal memory'' race. RRAMs have been the subject of academic research since the discovery of the electrical pulse induced resistance change effect in such films around 2000.

RRAM cells are usually two-terminal devices based on perovskite-oxide thin film materials. Resistive switching memories are based on materials whose resistivity can be electrically switched between high and low conductive states. RRAM is becoming of interest for future scaled memories, because of their intrinsic scaling characteristics compared to the charge-based flash devices, and potentially small cell size, enabling dense crossbar RRAM arrays using vertical diode selecting elements.

Over the years, a slew of companies have explored RRAMS--with little or nothing to show for it. Sharp, Sony, Samsung, LSI, Panasonic, Winbond, Unity, Hynix, Micron, Elpida and others have or are exploring RRAM. In fact, Japanese chip makers have reportedly poured a combined $100 million in RRAM development, but they have failed to deliver a product.

The latest major effort is taking place in Europe. In order to explore the scaling limitations of conventional flash memory cells, European research institute IMEC has started looking at RRAM cells. Five of the leading memory makers--Samsung Electronics Co. Ltd., Hynix Semiconductor Inc., Qimonda AG, Elpida Inc. and Micron Technology Inc.--are involved in the IMEC core CMOS research program and are set to share the cost and benefit from the results of the research.

IMEC's research activities on RRAM mainly focus on investigating the switching behavior of the RRAM cell concept that uses metal oxides as a switching element, and on demonstrating its scaling capability down to 25-nm. The leading material candidate is nickel-oxide, which has been the subject of study by Samsung at geometries greater than 100-nm.

At 4DS, the startup is taking a different approach than IMEC, but it did not reveal its secret sauce. The startup was formed in 2007, after it acquired some technology from an intellectual-property (IP) house. At the time, 4DS obtained some funding from PricewaterhouseCoopers and a number of investors in Australia and other regions.

By: DocMemory
Copyright © 2023 CST, Inc. All Rights Reserved