Asahi Glass Co., Ltd and a research group led by Koyanagi, professor of Graduate school of Engineering, Tohoku University, have succeeded in developing a new non-volatile memory, named Metal Nano Dot (MND) Memory. The MND memory is made using deposition technology of MND film based on ceramic technologies developed by Asahi Glass Co. The MND film is composed of extremely dense metal nanodots embedded in an insulating matrix. The MND memory is expected to replace existing flash Memory in the near future.
Demand to a high density and high performance non-volatile memory has rapidly grown as the market of mobile information devices has expanded in recent years, therefore many kinds of non-volatile memories have been proposed and investigated. Flash memory is the most widely used of the non-volatile memories, because of its high density, low manufacturing cost and stable operation and so on. However, scaling-down of the flash memory cell size has become more and more difficult because the tunneling oxide thickness can not be scaled down with the cell size due to the need to keep excellent charge retention and endurance. In order to solve this problem, new types of memory cells, such as silicon nanodot memory and MONOS memory, have been proposed. However, these memories do not have sufficiently high density of charge retention sites, therefore magnitude and uniformity of memory window are not enough. Professor Koyanagi paid attention to the MND film developed by Asahi Glass Co. to apply to new non-volatile memory and has worked with Asahi Glass engineers on the trial devices. The fabrication of the trial devices was carried out at Venture Business Laboratory of Tohoku University.