Ultra-Low-K dielectric degradation before breakdown

This paper presents a basic investigation of Ultra Low K (ULK) SiCOH dielectrics degradation before breakdown. For the first time very early stages of degradation before breakdown have been revealed and a theory of the basic process of ULK alteration under electrical stress has been proposed. Tip electrode test structures have been specifically designed for this investigation in order to determine the location of degradation and breakdown. A stepwise increased voltage stress test with a meticulously observed current in fA range was developed and successfully applied.