A Scalable Scr Compact Model For Esd Circuit Simulation

A scalable compact model for SCR-based electrostatic discharge (ESD) protection devices is presented. This model captures the effect that layout spacing has on SCR characteristics, such as holding voltage and trigger current. The model also captures both the delayed turn-on of the SCR, which results in large voltage overshoots during fast rise-time ESD events and the charge removal mechanisms that underlie the turn-off transient. Bias and time dependences of SCR on-resistance are captured with a resistance model that accounts for self-heating.