A Thermodynamic Framework for Reliability Kinetics

Area of Science:

• Materials Science
• Physics
• Engineering

Background:

• Power-law relationships are crucial for modeling degradation kinetics and predicting device lifetime in reliability physics.
• These relationships apply to diverse failure mechanisms like time-dependent dielectric breakdown (TDDB), hot-carrier injection (HCI), bias temperature instability (BTI), electromigration (EM), and fatigue.

Purpose of the Study:

• To develop a unified thermodynamic framework for reliability kinetics.
• To generalize kinetic equations by incorporating thermal activation, stress acceleration, and accumulated degradation.
• To introduce degradation correlation as a key descriptor for reliability modeling.

Main Methods:

• Derivation of a generalized kinetic equation from Gibbs free energy and entropy partitioning.
• Introduction of a stress coefficient (γ) and a correlation coefficient (χ).
• Interpretation of established reliability mechanisms within the new thermodynamic framework.

Main Results:

• The framework successfully interprets various degradation behaviors: TDDB (independent), HCI (self-limiting), BTI (strongly self-limiting), and fatigue (self-amplifying).
• Electromigration highlights the role of stress acceleration (γ).
• The correlation coefficient (χ) quantifies the influence of accumulated degradation on subsequent degradation.

Conclusions:

• The proposed thermodynamic framework offers a unified interpretation of empirical power-law degradation kinetics.
• Degradation correlation (χ) is identified as a vital complementary descriptor for accurate reliability modeling and lifetime prediction.
• This approach enhances the understanding and prediction of material degradation across multiple failure modes.