Modeling temperature effects of thick oxide 60Co induced degradation under low electric field. Hardness assurance implications

A code solving most of the known physical processes conducting to the MOS degradation under total dose constraint has been developed. Two lots of a power MOSFET have been exposed to Co⁶⁰ irradiations with various temperature and different bias conditions. The parameters used in the code have been adapted in order to fit the experimental results. According to the simulation results, the physical processes leading to the measured oxide trapped charge and interface traps dependencies are discussed. Different kinetics of degradation when switching the dose rate from high to low and the ELDRS are explained by the electric field inversion due to shallow trapped holes. An estimation of the very low dose rate degradation is done for devices sensitive to ELDRS.