On Nov. 21, Mr. Awano presented his recent work on long term reliability of VLSI circuits at VMC2013 held in San Jose.
Bias temperature instability (BTI) is considered to have significant impact on long term reliability of VLSI. At the workshop, he presented variability of BTI degradation measured on hundreds of transistors. Measuring BTI degradation has taken days or even weeks even in accelerated conditions. Hence, measurements of BTI on many transistors and analyzing its variability has been almost impossible.
He successfully shorted the measurement time by devising a circuit that overlaps the stress/recovery time over many transistors. By taking its variability into account, optimistic or pessimistic prediction of degradation can be prevented.