A defect-based compact modeling approach for the reliability of CMOS devices and integrated circuits

Reliability simulations are critical for lifetime prediction and verification of long-term performance of integrated circuits designed in advanced CMOS technologies. The existing techniques for reliability simulation model aging effects using threshold voltage (Vth) shifts that do not reflect the bias-dependence of stress-induced defects. In this work we present a defect-based modeling approach that captures the dynamic effects of both oxide-trapped charge and interface traps through calculations of surface potential. Such defects are attributed to aging effects and to ionizing-radiation damage in advanced CMOS technologies. The approach provides a connection between physics-based reliability models and integrated circuit simulation. The model is implemented as a Verilog-A sub-circuit module and is compatible with standard EDA tools and MOSFET compact models. The model formulation is verified using two-dimensional TCAD simulations. Demonstrations with digital integrated circuit simulations in SPICE and comparisons with calculations using Vth-based models are also presented.