Prototype rule-based reliability analysis for VLSI circuit design

This report describes the development and application of parametric and geometry based macro-models of hot-carrier induced dynamic degradation in MOS VLSI circuits. Previously, a simulation based approach has been used for reliability analysis, but this is inefficient for reliability assessment of very large scale integrated circuits. Geometry-based macro-models for hot-carrier reliability estimation have been developed. The macro-models express hot-carrier damage as functions of designable parameters such as transistor size (W), output loading capacitance (C1) and the input signal slew rate (a). A prototype rule-based reliability diagnosis tool, iRULE, has been developed. This tool uses the macro-models for designing hot-carrier resistant circuits without the need for transient reliability simulations. This provides the ability to analyze very large circuits with more than one million transistors on a workstation in a short amount of time. This report also describes a fast timing reliability simulation tool, ILLIADS-R, that can accurately estimate hot-carrier degradation while providing several orders of magnitude speed up over traditional transistor-level circuit simulators.