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Track 1 Session 5
9:10 to 10:10 a.m. Thursday March 26, 2009
Reliability Evaluation Using Step-Stress Testing Under Changing
Degradation Conditions
Ramp stress testing is a widely used technique for reliability
assessment. Dependent on sample size, stress profile and data accuracy, various techniques
in different forms exist which also extract long-term reliability parameters from these
short-term stress tests. To save time, high stress levels are applied to the device under
investigation. As the mechanism of degradation changes with the stress values exceeding a
certain threshold, a natural limit is set. It would be of great benefit to test at higher
levels to compensate for unwanted second order effects. This presentation will guide through
an example and explain how a natural changing degradation mechanism can be compensated for
accurate reliability evaluation.
Key Words: Step-Stress Testing, Time Varying Stress,
V-Ramp, Compensation of Changing Degradation Mechanisms, fWLR, Gate Oxide
Reliability, Cumulative Exposure Model, Modified Stress-Profile
Andreas Aal
ELMOS Semiconductor AG
Germany |
