Time-Dependent Dielectric Breakdown in 45-nm PD-SOI N-Channel FETs at Cryogenic Temperatures for Quantum Computing Applications

The aim of this paper is to analyze the time dependent dielectric breakdown (TDDB) in MOSFETs at cryo temperatures deployed in control circuitry for quantum computing applications. The effect of cryogenic temperatures down to 10K on TDDB in 45-nm RFSOI n-channel MOSFETs is studied here. From Weibull distribution, it is seen that the characteristic breakdown time (t63) increases with decreasing temperature with a weak saturation effect at ultra-low temperatures. Weibull slope (beta) shows an inverted U-shaped trend exhibiting a maximum between 100-200K at all measured voltages. Very low activation energy (Ea) is seen at cryo temperatures and Ea decreases with temperature lowering in three distinct temperature regions. The voltage acceleration exponent (VAE) increases with decrease in temperature down to similar to 77K followed by a decrease with decreasing temperature. The trap generation rate and critical defect density are estimated and the trend of beta is explained within the framework of the multiple origins of breakdown in the measurement window. Significant sample size for each condition with variability was taken into account for all parameters to improve the confidence level in our results.