Gigabit Logic Circuits with Scaled nMOS

Logic circuits made with a new scaled n-channel MOSFET technology have been clocked at gigabit rates. This new nMOS technology employs X-ray lithography and reactive ion etching to obtain 1 ¿m features and submicron channel lengths. Two ring oscillator designs are presentea: (1) circuits witra propagation aelays of 30 ps and power-delay products of 44 fJ and (2) circuits with power-delay proaucts of 5 fJ that have propagation delays of 75 ps. A practical logic circuit, a four-stage frequency divider or counter, is aescribed that has been operated at clock frequencies up to 2.5 GHz.