Effects of chemical interaction between Ta and SiOF on the crystallinity of Cu and Ta in Cu/Ta/SiOF films

Interactions between Ta and SiOF films were investigated. The effect of these interactions on the crystallinity of Cu and Ta films was also examined. It was found that much a rougher interface was formed at the Ta/SiOF interface than at the Ta/SiO(2) interface. This clearly resulted from a strong interaction between Ta and SiOF occurring through the defluorination of SiOF film during Ta sputter deposition. Ta oxides and fluorides were observed to form at the interface of Ta/SiOF, which resulted in the degradation of the Ta (002) texture. Furthermore: the degradation of Ta crystallinity led to the reduction of the Cu (Ill) texture by causing a deficiency in interfacial heteroepitaxiality.