STATISTICAL INVESTIGATION OF DIELECTRIC-BREAKDOWN OF BISMUTH TANTALATE THIN-FILM CAPACITORS

Dielectric breakdown of ferroelectric thin film capacitors is an extre mely important phenomenon that in general is not well understood. The importance of dielectric breakdown as it relates to the reliability of devices that utilize these structures can not be over emphasized. Oft en breakdown voltages are reported as a single value, measured off of a single device. Due to the large variability of thin film dielectric breakdown that is often present even within devices constructed on a s ingle substrate, a statistical investigation is the only meaningful wa y to present this data. This work details a preliminary statistical in vestigation into dielectric breakdown of strontium bismuth tantalate t hin film capacitors on platinum electrodes. A spin on process was used to deposit the ferroelectric film. Capacitors were fabricated through interconnect metalization. Breakdown voltage as a function of various methods of voltage stressing and temperature stressing is presented. Where possible, theoretical models are used to explain the dielectric breakdown mechanisms.