Fabrication and characterization of a quarter micron gate CMOS using ultra-thin Si film (30 nm) on SIMOX substrate

Deep submicron-gate MOSFETs have been fabricated on ultrathin Si film of 30 nm, 50 nm, and 100 nm in thickness on SIMOX (separation by implanted oxygen) substrates. CMOS ring oscillators of 51 stages were fabricated to evaluate propagation delay. A high performance of 21.5 ps/stage (V/sub D/=2.5 V at room temperature) was observed for a 0.25- mu m-gate CMOS ring oscillator on the SIMOX substrate with Si film of 100 nm in thickness. By reducing the thickness of Si film on SIMOX substrates down to 30 nm, excellent immunity from short channel effects that is, independence of threshold voltage from gate length and low subthreshold voltage swings, was found.<>