Softly, softly [CMOS scaling advances by subthreshold technology]

This article first of all outlines the operation of NMOS transistors operating in the strong inversion region. It then goes on to describe weak inversion, or subthreshold mode, operation and how this could be used to overcome the current scaling problems being encountered in CMOS IC manufacture. Also considered are the low-power operating advantages and current frequency limitations. Practical commercial implementations of this technology are presented along with forecasts for its future use in mainstream manufacture.