Current-voltage characteristics, dielectric breakdown and potential distribution measurements in Au-SiOx-Au thin film diodes and triodes

Vacuum-evaporated Au-SiOx-Au thin film cathodes with insulator thicknesses ranging up to approximately 6000 Å have been tested at direct voltages up to 60 V. In addition to exhibiting negative resistivity and single-hole dielectric breakdowns which have previously been observed at voltages leas than 20 V, these samples also showed a destructive breakdown mechanism at a voltage (V β) normally between 20 V and 30 V, which was independent of the insulator thickness. Increased device temperatures and wrinkling of the counter electrode indicated thermal processes at the voltage V β. These results may be explained in terms of a high field region within the insulating layer, where dielectric breakdown is initiated. The existance of such a region has previously been reported, and was confirmed in the present work.