Accurate evaluation of gate delay for low-power and high-density 0.18 μm CMOSFET technology

The gate delay of ring oscillators in high V_T CMOSFET technology is characterized with respect to various channel widths (0.72 μm-10 μm). An expression for gate delay including the channel-width independent capacitance components is derived and compared with experimental results. Substantial increase of gate delay in the narrow channel width region is found due to channel width independent capacitance components which are inherent to transistors. Although the channel width independent capacitance is negligible in wide channel width, gate delay of narrow channel width (⩽1 μm) ring oscillator increased more than 20% compared with 5 μm channel width ring oscillator