Determination of process-dependent critical spice parameters for application-specific ICs

The sensitivity analysis results are of fundamental importance to the VLSI design because it provides the information to identify a set of critical parameters for each fabrication technology. We have formulated a new sensitivity function to select the critical MOS parameters for digital and analog circuit designs using various MOSIS fabrication technologies. The most sensitive parameters with respect to the drain current have been found to be the gate-oxide thickness, threshold voltage, mobility, and body-effect coefficient. As for the transistor output conductance, the channel-length modulation coefficient and saturated carrier velocity are the most sensitive parameters in addition to those parameters mentioned above. The set of critical parameters plays an important role in the statistical circuit analysis where the worst/best-case parameter files have to be established and in the extreme-temperature circuit simulation.