Electrode-limited dielectric breakdown of alkali free glass

The dielectric breakdown statistics of alkali-free glass was determined for various thicknesses with electrodes having controlled morphology and continuity. The characteristic electrical breakdown field strength increased from 400 to 1100 MV/m as the glass substrate thickness decreased from 58 to 5 μm, respectively. Surface roughness RMS values of as-drawn and etched glass substrates were in the 0.9-1.8 nm range, which is small in comparison to the glass substrate thickness. The glass etching, itself did not have significant effect on the dielectric breakdown strength. The dielectric breakdown strength was also independent of the sputtered-deposited electrode composition (Au, Pt); however, electrode thickness played an important role in controlling the breakdown process. The Au electrode morphology transitioned from a continuous sheet for thicker electrodes to discrete nano-scale islands for very thin electrodes (<2 nm thick). The thin electrode morphology provides a unique opportunity to explore the intrinsic properties and high dielectric breakdown strength regime (1100 MV/m) in glasses with Weibull modulus values approaching 100.