December 2, 2005 – Researchers at Japan’s Nippon Telegraph & Telephone Corp. (NTT) have developed a way to fabricate functional resistance random-access memory (RRAM) using existing electronic materials, possibly opening a pathway to low-cost mass production of the technology touted as faster, low-power alternative to flash memory.
The Nikkei Business Daily reported that such devices typically require materials such as praseodymium, calcium, and manganese oxide, which are difficult to make into thin films and are not used in semiconductor manufacturing, meaning new processes would have to be developed to produce the nonvolatile memory.
But using ECR sputtering deposition methods, NTT’s Microsystem Integration Laboratories has fabricated 30-50nm-thick layers of bismuth titanium oxide, a ferroelectric material currently used for ferroelectric random-access memory (FeRAM) and smart cards, between two electrodes on a substrate.
The element exhibits properties of nonvolatile memory (switching with voltage is applied, but retaining its state when power is off). More work is needed to determine the mechanism of action of the device, the report noted.