Intel researchers working on long-term memory for chips

While performance-improving cache memory gets a lot of attention, there is an increasing need on today's chips for programmable read-only memory (PROM) as well. This is used to permanently store information for such user-visible features as code storage and on-chip encryption keys, as well as yield-enhancing functions such as cache repair and post-silicon circuit tuning. PROMs rely on electrical fuses for in-factory programming. Salicided polysilicon has traditionally served as a fuse element in several generations of CMOS technologies, but Intel's recent transition to high-k metal-gate technology requires a significant shift in fuse design to metal fuses. Intel has developed a new metal fuse-based 3-D high-density PROM technology that is fully compatible with high-k metal gate. The new technology has been developed for Intel's 32nm process, on which it has a 1.37 square micron cell. It is readily scalable for future logic technologies. Details are being described this week at the 2009 Symposia on VLSI Technology and Circuits in Kyoto, Japan.