Patent ID: 7064056
Filing Date: 2006-06-20
Classification: H01L

Abstract:
1. A method for forming an improved barrier layer stack for preserving an aluminum alloy interconnect resistivity comprising the steps of: 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 a titanium nitride (TiN) 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, wherein the exposed conductive region and the overlying aluminum alloy layer comprises an AlCu alloy; and, subjecting the semiconductor process wafer to at least one process comprising a temperature of greater than about 300° C.