Static RAM unlike dynamic RAM does not need to be periodically refreshed, but it is still considered volatile because its data is eventually lost if not powered. Although we don’t hear much about SRAM on the news, an important achievement has been made regarding this technology. IBM along with its development partners AMD, Freescale, STMicroelectronics, Toshiba and the College of Nanoscale Science and Engineering have created what they call the world’s first working 22-nm SRAM memory cell.
Researchers were able to achieve this by optimizing the SRAM cell design and circuit layout to improve stability, and used high-NA immersion lithography to print the pattern dimensions and densities. This is a significant development considering the current leading-edge of commercial SRAM manufacturing is based on the 45nm scale.
According to IBM, the creation of the new cell was aided by the use of band edge high-K metal gate stacks, transistors with less than 25nm gate lengths, thin spacers, novel co-implants, advanced activation techniques, extremely thin silicide, and damascene copper contacts. The company plans to reveal more details at the IEEE International Electron Devices annual meeting which will be held in December.