R.F.-sputtered tantalum-based diffusion barriers between copper and silicon

"There is clear need to apply copperfor metallisation in integrated mcircuits and micropackaging, but its usage has been hindered by chemical incompatibility of copper with silicon. However, tantalum-based diffusion barriers, like tantalum nitrides (Ta2N and TaN), seem to provide a feasible solution. In this study the effects of the reactive r.f sputtering process parameters on the formation of tantalum based diffusion barriers has been studied. Moreover, the evolution of various reaction products and their relation to the barrier properties are discussed"