Method of making a barrier layer for via or contact opening of integrated circuit structure

摘要

Described is a barrier layer in an integrated circuit structure which is formed in a via or contact opening over an underlying material in which diffusion of the underlying material (or filler material deposited over the barrier layer) through the barrier layer is inhibited without unduly increasing the thickness and resistivity of the barrier layer. This is accomplished by substituting an amorphous material for the crystalline titanium nitride to thereby eliminate the present of grain boundaries which are believed to provide the diffusion path through the titanium nitride material. In a preferred embodiment, the amorphous barrier layer comprises an amorphous ternary Ti-Si-N material formed using a source of titanium, a source of silicon, and a source of nitrogen. None of the source materials should contain oxygen to avoid formation of undesirable oxides which would increase the resistivity of the barrier layer. In a particularly preferred embodiment, an organic source of titanium is used, and either or both of the silicon and nitrogen sources are capable of reacting with the organic portion of the organic titanium reactant to form gaseous byproducts which can then be removed from the deposition chamber to inhibit the formation of carbon deposits in the chamber or on the integrated circuit structure.