Dielectric-breakdown and conduction-mechanism in a thinned alkali-free glass

The leakage current in alkali-free glass was analyzed to understand the dielectric breakdown behavior and the potential conduction mechanism. The dielectric breakdown strength and the leakage current were increased after the thickness of the glass had been recuded. To identify the predominant conduction mechanism, we carefully interpreted the dc voltage-current curves via fitting with various conduction mechanisms, e.g.) Poole-Frenkel emission, Schottky emission, space-charge-limited current, and hopping conduction. The result suggested that the space-charge-limited current and the hopping conduction of thermally-excited carriers were the most likely mechanisms of conduction in alkali-free glass.