Dependence of breakdown field on dielectric (interelectrode) thickness in base-metal electroded multilayer capacitors

The authors have empirically determined the dependence of breakdown field E-B versus dielectric thickness d (electrode separation) for a large number (4100) of BaTiO3-based multilayer capacitors with Ni base-metal electrodes. The data averaged over lateral area show for 6 < d < 22 mu m that E-B=constxd(-n), where n=0.50 +/- 0.06, a result compatible with macroscopic "thermal" dc breakdown mechanisms. More precisely, however, the results nearly perfectly fit a situation of breakdown occurring in connected defects from collision ionization resulting from field emission from the cathode. (c) 2007 American Institute of Physics.