Thermochemical description of dielectric breakdown in high dielectric constant materials

A thermochemical/molecular model is developed for breakdown in high dielectric constant materials and the model suggests that a fundamental relationship exists between dielectric breakdown strength (E-bd) and dielectric constant (k). The model indicates that E-bd should show an approximate (k)(-1/2) dependence over a wide range of high dielectric constant materials. The model also predicts that the field-acceleration parameter (gamma), from time-dependent dielectric breakdown (TDDB) testing, should increase with dielectric constant. TDDB and E-bd data are presented for model support. The thermochemical model suggests that the very high local electric field (Lorentz-relation/Mossotti-field) in high-k dielectrics tends to distort/weaken the polar molecular bonds making them more susceptible to bond breakage by standard Boltzmann processes and/or by hole capture and thus lowers the breakdown strength. (C) 2003 American Institute of Physics.