Modeling of time-dependent variability caused by Bias Temperature Instability

Abstract

In small devices, Bias Temperature Instability (BTI) produces discrete threshold voltage (VT) shifts, which are attributed to the charge and discharge of single defects. A deep knowledge of the properties of these defects is required in order to correctly evaluate the BTI degradation in devices. In this work, these defects are experimentally characterized. Their properties are the input parameters to a previously presented BTI physics-based model that allows the evaluation of the corresponding VT shift. The model has been included in a circuit simulator. As an example the BTI effects on SRAM performance on SRAM cells performance and variability is studied.