An efficient improvement for barrier effect of W-filled contact

A post chemical vapor deposition of tungsten (CVD-W) treatment by N 2 plasma is proposed to suppress the WAl 12 formation during subsequent thermal annealing, which improves the thermal stability of W-filled contact. Selective CVD-W is employed to fill the contact hole. Following W deposition, in situ N 2 plasma treatment is performed prior to Al alloy metallization. It is shown that this post CVD-W treatment efficiently suppresses the formation of WAl 12 , resulting in an improvement of the barrier capability of W-filled contact.