A Cu seed deposited by chemical vapor deposition (CVD) was integrated with a CVD TiN barrier and electroplated Cu in a double level metal interconnect scheme using a dual damascene process. The post-SiH 4 treatment of CVD TiN inhibits agglomeration of thin Cu by improving the wettability of Cu seeds as well as reducing the TiN sheet resistance. Post-plasma treatment on CVD Cu seeds decreases impurities in CVD Cu and eliminates interface voids between the CVD Cu seed and electroplated Cu, improving the gap filling properties of electroplated Cu layers. Inherently poor adhesion of the CVD Cu layers between the Cu barrier metal and the electroplated Cu is overcome by CVD TiN post treatments and CVD Cu post-plasma treatment. Bias-thermal-stress (BTS) tests were performed to verify the effect of post-SiH 4 treatment. The SiH 4 treated CVD TiN barrier and CVD Cu seed show feasibility for 65-nm technology in terms of low via resistance and chain yields.

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