Ferroelectric RAM - Fast write, Low power, and Endurance
It was gratifying to all pioneers in ferroelectric random access memory, or FeRAM, when a Panasonic chip with Symetrix FeRAM technology was introduced in the commuter fare card by Japan Railway in 2008. This fare card was far more sophisticated, reliable and secure than its nearest rivals, and the FeRAM “inside” gave the feeling of instantaneous response. Today, it is the backbone of an ever expanding e-cash system in Japan.
FeRAM technology is now in the commercial mainstream and contributing to the success of several Symetrix licensees and other suppliers of products that incorporate FeRAM. Fast write, low power and endurance, these are the metrics that separate FeRAM from other non-volatile memory (NVM), and these metrics have more relevance today. Not surprisingly, the interest in FeRAM has been resurgent, and not just in FeRAM memory. There are a range of functionalities that are enabled by ferroelectric materials, such as sensors and actuators, which may be combined with memory. Networks of remote sensors, for example, that write copious data to memory need a fast write, low power memory to keep up and keep on. And where harvested energy is desired, FeRAM performs substantially better, where another NVM may not perform at all.
So far, FeRAM has been commercialized as a stacked capacitor at 130nm. Alternative FeRAMs will arrive with new CMOS architectures. 3D transistors, for example, may result in new modes of FeRAM memory operation (e.g., modulation of the depletion region instead of stored charge). New materials are required for these new modes and there are several strong candidates under investigation at Symetrix.
Symetrix Patented SBT Layered Super Lattice