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 WAl12 formation during subsequent t hermal annealing, which improves the thermal stability of W-filled con tact. Selective CVD-W is employed to fill the contact hole. Following W deposition, in situ N-2 plasma treatment is performed prior to Al al loy metallization. It is shown that this post CVD-W treatment efficien tly suppresses the formation of WAl12, resulting in an improvement of the barrier capability of W-filled contact.