Elpida, the world’s third largest DRAM manufacturer, just announced successful development of a 64Mbit resistive RAM (ReRAM) prototype chip using a 50nm process technology. Two key specs for this prototype are a 10nsec write speed, similar to DRAM and orders of magnitude faster than NAND Flash memory, and a write endurance rating of more than one million cycles, an order of magnitude better than NAND Flash memory. Both characteristics are essential for any new memory technology that would challenge the dual dominance of DRAM and NAND Flash semiconductor memory.
However, no one is going to get excited about a commercial 64Mbit device when NAND Flash memories and DRAM chips are already available in Gbit densities. So Elpida is planning on using 30nm process technology to build denser (and presumably faster) ReRAM devices with Gbit capacities.
Elpida’s announcement includes Sharp Corp, the University of Tokyo and Japan’s National Institute of Advanced Industrial Science and Technology (AIST), the New Energy and Industrial Technology Development Organization (NEDO), and the University of Tokyo as partners on the ReRAM project. Although it’s not discussed in the press release, according to a presentation made by Deepak Sekar, Chief Scientist at Monolithic 3D, the Sharp ReRAM memory element is based on the movement of oxygen atom vacancies within a TiON layer—a mechanism quite similar to the one described by HP in reference to its memristors.