4DS will collaborate with Sematech’s memory program to build a full transistor-memory to demonstrate a working prototype of a low power RRAM device based on 4DS’ proprietary material processes and device structures.
In 2009, startup 4DS emerged and claimed to have made a major breakthrough in resistive random access memory (RRAM) technology. 4DS is a privately-held U.S. corporation and a subsidiary of 4D-S Pty. Ltd. an Austrialian firm. Right now, the company has ”prototype devices in development,” said Kurt Pfluger, chief executive of 4DS, in an e-mail.
FeRAM, MRAM, phase-change and RRAM are considered next-generation memory technologies. RRAM, a next-generation non-volatile memory technology, is attractive as a replacement for flash memory and as a complement for non-volatile memory applications due to its speed, power profile and scaling. One of the obstacles in deploying RRAM has been establishing a stable memory element. The race to develop circuits has left a gap for development of reliable materials and deposition techniques for low cost manufacturing.
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 superior 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. RRAM is seen as a potential candidate to replace conventional flash memory at or below the 22-nm manufacturing process technology node.
“4DS’ unique expertise in RRAM materials technology will complement our device, process and characterization expertise,” said Raj Jammy, vice president of emerging technologies at Sematech, based in Albany, N.Y. ”The joint partnership will expand on Sematech’s current collaborative efforts to develop suitable materials and process techniques for future non-volatile memory applications.”
The 4DS platform for non-volatile memory is a low temperature CMOS compatible, back end of line (BEOL) process with a simple structure that requires fewer mask steps than flash memory. It operates with lower power and writes faster than conventional flash memories. No other details were given.
Others are also devising RRAM-like products. Adesto Technologies Corp.-a memory startup funded by Applied Materials Inc. and others-is readying its first product-a conductive-bridging RAM (CBRAM).
Seeking to commercialize its memristor technology, Hewlett-Parkard Co. last year entered into a joint development agreement with South Korea’s Hynix Semiconductor Inc. HP and Hynix will jointly develop new materials and process integration technology to transfer HP’s memristor technology from R&D to commercial development in the form of resistive random access memory (RRAM).
In order to explore the scaling limitations of conventional flash memory cells European research institute IMEC recently started looking at RRAM cells. Five of the leading memory makers — Samsung, Hynix, Elpida and Micron Technology — are involved in the IMEC core CMOS research program and are set to share the cost and benefit from the results of the research.
Another firm, Unity Semiconductor Corp., recently ousted its chief executive and the company is moving from a fab to an intellectual-property (IP) model. Micron has made a small investment in Unity. Unity will have access to Micron’s 300-mm fabs.