Compact In-Situ Sensors for Monitoring Negative-Bias-Temperature-Instability Effect and Oxide Degradation

The NBTI sensor proposed is intended to be used for general NBTI characterization and not in- situ monitoring of degradation, due to large area overhead (~450x area of NBTI sensor in this work), inability to correct for temperature variations encountered during operation and the analog output of the sensor. We introduce two compact structures to digitally quantify the change in performance and power of devices undergoing NBTI and defect-induced oxide breakdown. The small size of the sensors makes them amenable to use in a standard-cell design with low area and power overhead. The sensors can be implemented in large numbers to collect data on degradation and statistical performance of the devices.