Russia, U.S. get closer to universal memory

April 20, 2016 // By R. Colin Johnson
Researchers from the Moscow Institute of Physics and Technology (MIPT), the University of Nebraska (USA) and the University of Lausanne (Switzerland) have collaborated to grow an ultra-thin ferroelectric film on silicon, which they believe could become the favoured "universal" non-volatile memory material of the future, as well as for memristors in brain-line cognitive neuromorphic computers.

Researchers worldwide are seeking a "universal" memory to replace DRAM, SRAM, flash and spinning-disks. Of the many proposals being researched, this one has the advantage of being fabricated on a silicon substrate with conventional tools; it's also potentially fast, dense and nonvolatile, plus could be adapted to operate like an artificial neuromorphic synapse, too—a memristor—making it suitable for both conventional computers and the cognitive computers—cognizers—of the future.

The material is an ultra-thin (2.5-nanometer) polycrystalline ferroelectric film on silicon invented through a collaboration among the MIPT, the University of Nebraska and the University of Lausanne (Switzerland).

Fig. 1: A silicon-based ferroelectric tunnel junction is written by applying an external electric field, which changes the direction of the ferroelectric’s polarization vector and thus the shape of the potential barrier. (Source: Moscow Institute of Physics and Technology (MIPT))

"The difference between our approach and other attempts to grow ultra-thin ferroelectric films, particularly, on silicon, is that we grow polycrystalline (rather than epitaxial) alloyed hafnium-zirco­nium [Hf-Zr] oxide films, which retain their ferroelectric properties down to thicknesses of under three nanometers," said Andrei Zenkevich, head of MIPT's Laboratory of Functional Materials and Devices for Nanoelectronics, told EE Times.