In-Situ Monitoring of Oxide Ion Induced Breakdown in Amorphous Tantalum Oxide Thin Film Using Acoustic Emission Measurement

Abstract

An acoustic emission (AE) measurement was employed under DC bias applied condition to investigate breakdown behavior of highly resistive tantalum oxide thin film induced by redox reaction of oxide ion and its resultant generation of oxygen gas. Above dc bias of 14 V, AE event with strong components around 400 kHz and below 100 kHz was detected only once just after the bias was applied. On the other hand, a number of AE events were intermittently observed at 20 V, where the resistivity of the film drastically dropped. The behavior indicates oxygen gas was generated at the bottom electrode interface and released due to forming of a blister as large as several hundreds of micrometers.