An Investigation of Time Dependent Dielectric Breakdown (TDDB) on Carbon Nanotube Field-Effect Transistors (CNTFETs)

As technology nodes continue to scale down, silicon-based integrated circuits have approached physical limits. In order to sustain Moore's Law, new materials have become a major focus of research in the field of integrated circuits, with carbon-based integrated circuits considered one of the most promising new materials due to their superior electrical characteristics. Currently, reliability is a primary concern constraining the development of carbon-based integrated circuits. Time-dependent dielectric breakdown (TDDB) is a common reliability issue in field-effect transistors, and it is also prevalent in CNTFETs. This paper employs the measure-atress-measure (MSM) method to investigate the TDDB phenomenon in CNTFETs, applying 3 different constant electrical stress on multiple devices and extract the time to breakdown (tbd). Experiment results show tbd follows weibull distribution, same as silicon MOSFETs, but with a much smaller voltage accelerate factor of 16.91 compare to the typical values of silicon. It is speculated this might be due to the inferior oxide/CNT interface quality compared to silicon allows generated trap to form a leakage path under relatively low electric filed stress.