The startup, Adesto Technologies Inc., is developing a technology based on a RRAM-type scheme called programmable metallization cell (PMC). Adesto licensed the PMC technology from Axon Technologies Corp., a spinoff of Arizona State University.

RRAM is seen as a potential candidate to replace conventional flash memory at or below the 22-nm process technology node. Other candidates include 3-D, FRAM, MRAM and phase-change.

Two-year-old Adesto plans to sample a next-generation memory line based on PMC within a year, said Ishai Naveh, co-founder and vice president of marketing and business development for the company.

The company is pushing its devices for the embedded and storage-class memory field, he told press at the Flash Memory Summit. Adesto was started by executives from AMD, Tower and other firms. It has received one round of funding and is looking to close on another. One of its investors is fab tool giant Applied.

There is a slew of activity in RRAM. 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.

PMC is one of the flavors of RRAM. ''The mechanism that defines memory behavior is a proprietary Axon process and uses a thin amorphous film with two metal contacts,'' according to Axom's Web site. ''It makes use of a little-known feature of some amorphous materials that they can incorporate relatively large amounts of metal and behave as solid electrolytes. Under appropriate bias conditions, the metal ions in the electrolyte can be reduced to form a conducting pathway through the material but the process can easily be reversed to recreate the insulating amorphous layer.''

In 2004, Infineon Technologies AG signed a non-exclusive license for Axon's technology. The technology did not appear to fly at Infineon. Micron Technology Inc. also signed a non-exclusive license for the technology in 2001.

In order to explore the scaling limitations of conventional flash memory cells European research institute IMEC recently started looking at RRAM. Leading memory makers -- Samsung Electronics Co. Ltd., Hynix Semiconductor inc., Elpida Inc. and Micron -- are involved in the IMEC core CMOS research program and are set to share the cost and benefit from the results of the research.

Fujitsu, Sharp and others are also looking at the technology. Another company, Hewlett-Packard, hopes RRAMs will open the floodgates for its so-called memristor technology.

4DS Inc. recently emerged from stealth mode and claims to have made a major breakthrough in RRAM technology. 4DS is a subsidiary of an Australian company called 4D-S Pty. Ltd.

By: DocMemory
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