Near speed-of-light signaling over on-chip electrical interconnects

The propagation limits of electrical signals for systems built with conventional silicon processing are explored. A design which takes advantage of the inductance-dominated high-frequency regime of on-chip interconnect is shown capable of transmitting data at velocities near the speed of light. In a 0.18-μm six-level aluminum CMOS technology, an overall delay of 283 ps for a 20-mm-long line, corresponding to a propagation velocity of one half the speed of light in silicon dioxide, has been demonstrated. This approach offers a five times improvement in delay over a conventional repeater-insertion strategy.