Method of depositing a tantalum nitride/tantalum diffusion barrier layer system

摘要

We have discovered a method of providing a thin, approximately from about 2 Å to about 100 Å thick Ta_N seed layer, which can be used to induce the formation of alpha tantalum when tantalum is deposited over the Ta_N seed layer. Further, the Ta_N seed layer exhibits low resistivity, in the range of 30 μΩcm and can be used as a low resistivity barrier layer in the absence of an alpha tantalum layer. In one embodiment of the method, a TaN film is altered on its surface to form the Ta_N seed layer. In another embodiment of the method, a Ta film is altered on its surface to form the Ta_N seed layer.