Physics-based Analytical Modeling of CMOS Latchup

TL;DR

This paper develops a physics-based analytical model for CMOS latchup, deriving explicit formulas for key parameters like holding voltage, current, and critical charge, considering physical and technological factors.

Contribution

It introduces a new analytical approach using Kirchhoff equations and equivalent circuits to model CMOS latchup behavior based on physical parameters.

Findings

Explicit formulas for holding voltage and current.

Critical charge for latchup as a function of process parameters.

Influence of temperature and doping on latchup parameters.

Abstract

Analysis of the steady-state Kirchhoff equations within the framework of a new physics-based equivalent circuit provides explicit expressions for the holding voltage and current for the resistive mode in bi-stable CMOS structures. The resulting expressions are functions of the physical parameters (temperature, doping level of the substrate, material band gap), which makes it possible to evaluate the influence of technological factors on the latchup parameters. In particular, an explicit formula was obtained for the critical charge for single event latchup as a function of process parameters and temperature.