The present invention relates to the formation of an ILD layer while preventing or reducing oxidation of the upper surface of a metallic interconnect. Avoidance of oxidation of the upper surface of a metallic interconnect is achieved according to the present invention by passivating the exposed upper surface of the metallic interconnect prior to formation of the ILD. In order to avoid the oxidation of an upper surface of an interconnect during the formation of an ILD layer, an in situ passivation of the upper surface of the interconnect, immediately prior to or simultaneously with the formation of the ILD layer avoids the problems of the prior art.