December 2016

2016 is soon over - and it was an eventful year for the RRAM industry. We have seen new RRAM devices demonstrated by several companies, encouraging words from industry leaders and Fujitsu's first RRAM chip.

Here are the top 10 stories posted on RRAM-Info in 2016, ranked by popularity (i.e. how many people read the story):

1. Strategic Elements developed transparent RRAM devices, endures 100,000 test cycles (Jun 3)
2. Western Digital: RRAM is the technology of choice for Storage Class Memory (Aug 12)
3. Fujitsu launches its first RRAM chip, the 4Mb MB85AS4MT (Oct 27)
4. Samsung will be ready soon with RRAM chips (Apr 21)
5. Panasonic demonstrate battery-less NFC electronic shelf labels with its ReRAM MCUs (May 14)
6. Researchers developed a high-performance 3D vertical crossbar array (Jul 14)
7. SanDisk expects RRAM to enter the enterprise storage market in 2018 (Mar 16)
8. Adesto introduces new ultra low-power CBRAM chips (Mar 7)
9. Intermolecular offers its ReRAM technology for licensing (May 6)
10. Yole Developpement sees $4.6 billion in sales of MRAM, RRAM and PCM memories generating $4.6 billion in 2021 (Jul 28)

Researchers from the Korea Advanced Institute of Science and Technology (KAIST) developed a security RRAM device that can be dissolved in water in less than 10 seconds. The idea, it seems, is that this kind of device can be disposed of quickly and safely.

The RRAM device was produced on a solid sodium glycerine (SSG) substrate, which is water soluble. The RRAM chip itself was deposited using an inkjet-printer.

Researchers from Leti presented a new paper that clarified for the first time the correlation between endurance, window margin and retention of RRAM. The researchers advice ways module these three key properties, in different RRAM types.

Each RRAM type and base material has a different "sweet spot" that offers the best performance in all three categories. Using modelling the researchers were able to address various non-volatile memory applications, targeting high speed, high endurance or high stability.

Adesto Technologies announced a new family of ultra-low power serial EEPROM memory based on its CBRAM RRAM technology aimed towards IoT devices. The Mavriq DS (which stands for Digital Security) offers low-power operation, excellent endurance and special security features.

Adesto says that its new chips performs read and write operations with 4x less power than competitive solutions, and, in ultra-deep power down mode, uses as much as 50x less power. DS devices can automatically enter the ultra-deep power down mode following write operations, reducing controller operations and overall system energy. The mavriq DS supports over 100,000 write cycles across the full temperature and voltage range.

US-based RRAM developer 4DS Memory announced that it has measured the endurance yield of more than 1,000 cells of five different cell sizes on two different wafers, and more than 97% of the memory cells tested achieved the required endurance goal, significantly exceeding the target of 90% endurance yield.

4DS recently announced the fabrication of a working 40nm RRAM memory cell in collaboration with HGST, a subsidiary of Western Digital. The company also successfully completed a placement of $3 million USD.

Researchers from Stanford University are studying filament RRAM technologies to discover the fundamental behavior of these memory cells. The research team built a tool to measure the basic forces that make RRAM chips work - especially the heat requirements for RRAM switching.

Using micro thermal stage (MTS) devices, RRAM chips were studied under a wide range of temperatures, to try and find the exact temperature in which RRAM switching occurs. It was discovered that operating at 80 to 260 F is more efficient than the higher temperatures people thought were more efficient.

Researchers at the Chinese Academy of Sciences developed a new cation-based RRAM device in which a single layer graphene was used as an ion barrier. Experiments indicate that this device is more reliable than previous RRAM designs while still maintaining high performance.

This work follows a recent discovery by the research group that there is a competition between the SET and RESET process in cation-based RRAM, which causes failure of reset operation in the RRAM device. The researchers found that the active metal which forms a conductive filament can diffuse into the Pt electrode under the action of an electric field, and form an additional active metal source in Pt electrode, which caused the failure of reset operation. Using graphene as an ion barrier is a solution to this problem.