Measurements and analysis of process variability in 90nm CMOS

Process variability in deeply scaled CMOS has both random and systematic components, with a varying degree of spatial correlation. A test chip has been built to study the effects of circuit layout on variability of delay and power dissipation in 90nm CMOS. The delay is characterized through the spread of ring oscillator frequencies and the transistor leakage is measured by using an on-chip ADC