A Charge-to-Breakdown (Q_BD) Approach to SiC Gate Oxide Lifetime Extraction and Modeling

Abstract

This paper proposes a charge-to-breakdown (Q <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BD</inf> ) approach for SiC/SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> dielectric lifetime extraction. The current through the dielectric is shown to be a combination of Fowler Nordheim (FN) and thermally assisted tunneling (TAT). The former leads to positive charge trapping, the latter to negative charge storage in border traps near the SiC/SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> interface. Both degradation mechanisms have a distinctly different failure distribution function. Time-to-fail extracted from constant field TDDB (standard industry technique) is unable to capture the effects of these different charge trapping mechanisms on the failure distribution function, in contrast to constant current Q <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BD</inf> stress. Hence, time-to-fail from Q <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BD</inf> stress leads to a more accurate and physics based lifetime prediction.