Krzysztof Domanski

A Charged Device Model (CDM) simulation method has been demonstrated to predict CDM fail current of receiving circuits with gate oxide connected to pad. This method involves inclusion of 20ps rise time edge into the stimulus. It was shown previously that this fast rise time component of the pulse can cause the gate oxide damage. The simulation method is intended as a schematic-level tool during pre-silicon design phase to deliver CDM ESD protection. Simulation results are verified by silicon results with qualification CDM test on package and Transmission-Line-Pulse (TLP) measurements on wafer-level.

In Part 1 of the article, we reviewed what EDA tools are good for. Here we will discuss EDA tool limitations.

Going back several decades, Electrostatic Discharge (ESD) design and layout checks that were done manually were laborious and time-consuming, let alone not confidently reliable.

CDM discharges exhibit a fast initial current step when the stray capacitance of the pogo pin is charged. It is demonstrated that the high slew rate can damage sensitive gate oxides. The miscorrelation of CDM and CC-TLP methodologies is addressed by applying pulses with 20 ps rise time.