An improved barrier layer stack and method for forming the same for preserving an aluminum alloy interconnect resistivity, the method comprising providing a semiconductor process wafer comprising an exposed conductive region; forming a first barrier layer comprising a barrier layer stack over the exposed conductive region comprising one of a TiN or Ti layer in contact with the conductive region; forming at least one additional barrier layer comprising the barrier layer stack to form an alternating sequence of TiN and Ti layers; forming an uppermost barrier layer of TiN comprising the barrier layer stack; forming an overlying aluminum alloy region in contact with the uppermost barrier layer; and, subjecting the semiconductor process wafer to at least one process comprising a temperature of greater than temperatures greater than about 350° C.