The Relation Between Degradation Under DC and RF Stress Conditions

In this paper, we develop a method to derive degradation formulas for time-varying stress from the formulas for the constant-bias case, discuss its limitations, and apply it to a set of radio-frequency (RF) stress experiments. First, we will give a new derivation of the well-known power-law case without invoking any specific physical degradation model. Next, we will show that this derivation can be generalized to the broader class of degradation functions of type g(f(Vi)·t). We will illustrate our work with an example of hot-carrier degradation in 45-nm n-channel metal-oxide-semiconductor field-effect transistors, where an accurate prediction of the measured lifetime under RF stress conditions is obtained from the measured degradation under direct-current stress.