The project is part of DARPA’s Electronics Resurgence Initiative (ERI) to develop new computing materials, designs and architectures. ERI has a budget of hundreds of millions of dollars to be spent over the next four or five years. The goal of the particular project is to speed up neural network processing while improving power efficiency through the use of analog signal processing as compared to current digital approaches.
The CeRAM – or Correlated-Electron RAM – is a form of non-filamentary, non-volatile memory based on metal-insulator Mott transition in nickel oxide and other transition metal oxides (TMOs). Because the switching effect is based on state transition throughout the material rather than the migration of ions or vacancies it is expected to have superior endurance and reliability. Carlos Paz de Araujo, a professor at the University of Colorado who is the leading advocate for development of the memory, has led much of the work on the technology through his company Symetrix Corp. (Colorado Springs, Colo.).
In 2014, when Professor had already been working on the technology for about five years, the claim was that with nickel oxide the state was robust up to 400 degrees C and can be read with a voltage of 0.1 to 0.2 volts. Devices albeit at large geometry were reported to have 10^12 cycles read endurance.
In 2014 Professor Araujo secured support from ARM for continued research into CeRAM as an embedded non-volatile memory that could potential have superior properties to flash memory and the various two-terminal ReRAMs that are in development or coming to market (see ARM’s turn to non-volatile memory is right move). If CeRAM is truly bulk switching it could have a scaling advantage over filamentary ReRAMs that may struggle to go below 10nm just as flash memory struggles to scale below 28nm.
Next: DARPA recognition
It is thought that ARM is a main licensee of the CeRAM technology from Symetrix and that Applied Materials has been exploring atomic layer deposition with the various material combinations that may display the correlated electron effect.
Although Professor Araujo started his Correlated-Electron RAM research with nickel oxides other materials such as hafnium oxide may be more familiar and easy to integrate with CMOS circuitry in commercial wafer fabs. ARM and Symetrix have been quiet about progress with CeRAM since 2014 but the technology clearly shows enough promise to have attracted DARPA’s support.
“This project is a perfect example of how new materials and architectures can be developed to enable new ways to accelerate artificial intelligence applications as classic Moore’s Law scaling slows,” said Steve Ghanayem, senior vice president of new markets and alliances at Applied Materials, in a statement. “Applied has the industry’s broadest portfolio in materials engineering capabilities and is excited to be part of a team enabling breakthroughs for artificial intelligence.”
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