Reliability Characterization of Ring Oscillator Circuits for Advanced CMOS Technologies

摘要

Ring-Oscillator (RO) are most suitable to investigate the reliability of digital CMOS circuits operating up to GHz frequencies as a good correlation has been observed between RO degradation and Product Fmax degradation. In addition, the RO degradation testing can be performed with similar equipment used for discrete device reliability characterization. In this work, we discuss the role of BTI/HCI contribution in RO degradation and compare the contributions of NFET and PFET devices. To decouple BTI/HCI contribution, AC characterization on discrete devices is conducted and correlated to the RO degradation under diverse testing conditions. Additionally, specially designed reliability RO are used to quantify device type contribution under RO stress.