Assessment of temperature and voltage accelerating factors for 2.3–3.2 nm SiO2 thin oxides stressed to hard breakdown

The temperature and voltage acceleration for a large database of time dependent dielectric breakdown in 2.3 and 3.2 nm SiO2 oxides is investigated. All results deal with the time to hard breakdown which is defined when a typical high current limit (1 mA) at operating voltage is reached rather than detecting the first current change as is conventionally done. Using an accurate experimental error evaluation, long range data are compared for consistency to the predictions of various state-of-the-art extrapolation models used to qualify these oxides, to point out which one describes the data best. The activation energies corresponding to the dominant degradation mechanisms are extracted over a temperature range from 50 °C to 125 °C for N type substrate stressed in accumulation regime. The voltage extrapolation models are compared for P and N type substrate with positive stress polarity on the gate. It is verified that a TDDB power voltage law is well predictive for both P substrate in inversion regime and N substrate in accumulation regime.