Comparison of Extraction Methods for Threshold Voltage Shift in NBTI Characterization

Negative bias temperature instability (NBTI) is a major concern for CMOS reliability. In this paper extraction methods for threshold voltage shift from drain current versus gate voltage transfer curve and from single drain current value in NBTI characterization of PMOS 3.3 V device in a 180 nm CMOS process were compared with good agreement from ultra-fast measurements at microsecond time scale. The analysis provides validation methodology of spot drain current measurement for fast determination of threshold voltage shift in NBTI characterization for the specific technology and device. After validation, spot current method can be applied to standard testers as well as test systems with fast measurement capabilities.