Characterization and modeling of charge trapping: From single defects to devices

Abstract

Using time-dependent defect spectroscopy measurements on nanoscale MOSFETs, individual defects have been characterized in much greater detail than ever before. These studies have revealed the existence of metastable defect states which have a significant impact on the capture and emission time constants. For example, these defect states explain the large emission time constants observed in bias temperature measurements as well as the switching behavior of defects sensitive to gate bias changes towards accumulation. By carefully analyzing the properties of the defects contributing to random telegraph noise and the recoverable component of the bias temperature instability, it could be confirmed that both phenomena are due to the same type of defect. The most fundamental property of these defects is that their time constants are widely distributed, leading to the ubiquitous time and frequency dependence. By transferring this knowledge to large area devices, noise as well as the response to bias temperature stress and recovery can be understood in great detail.