Analog Circuit Reliability in Sub-32 Nanometer CMOS: Analysis and Mitigation

The paper discusses reliability threats and opportunities for analog circuit design in high-k sub-32 nanometer technologies. Compared to older SiO2 or SiON based technologies, transistor reliability is found to be worse in high-k nodes due to larger oxide electric fields, the severely aggravated PBTI effect and increased time-dependent variability. Conventional reliability margins, based on accelerated stress measurements on individual transistors, are no longer sufficient nor adequate for analog circuit design. As a means to find more accurate, circuit-dependent reliability margins, advanced degradation effect models are reviewed and an efficient method for stochastic circuit reliability simulation is discussed. Also, an example 6-bit 32nm current-steering digital-to-analog convertor is studied. Experiments demonstrate how the proposed simulation tool, combined with novel design techniques, can provide an up to 89% better area-power product of the analog part of the circuit under study, while still guaranteeing a 99.7% yield over a lifetime of 5 years.

ISBN:9783981080179

Publication year:2011

BOF-keylabel:yes

IOF-keylabel:yes

Authors from:Higher Education