THREE-LAYERED BARRIER LAYER STRUCTURE WITH TOP LAYER HAVING GRADIENT COMPOSITION

PROBLEM TO BE SOLVED: To improve the performance of electron transfer and to make lithography process steps advantageous by raising an aluminum ä111} content of a barrier layer. SOLUTION: When a (Ti or TiNX)/TiN/TiNXbarrier layer is deposited using IMP techniques, the (Ti or TiNX)/TiN/TiNXbarrier layer can be improved by increasing the thickness of the first layer of Ti or TiNXto a range from about 100 to about 500 (the feature geometry controls the upper thickness limit), decreasing the thickness of the TiN second layer of TiN to a range from about 100 to about 800 (preferably less than about 600 ), and controlling formation of the third layer of TiNXto provide a Ti content ranging from about 50 atomic% titanium (stoichiometric) to about 100 atomic% titanium. In the case that the first layer is TiNX, atomic% of Ti is at least about 40. COPYRIGHT: (C)2009,JPO&INPIT