CVD Al/PVD Al integration for advanced via and interconnect technology

A metallization process that can fill the ever-shrinking vias and form the interconnect at the same time is highly desirable. An integrated Al plug and interconnect process offers advantages of improved electrical performance, and reduced cost of ownership through process simplification for 0.25 μm and beyond. In this report, an enabling technology that integrates Al deposited by chemical vapor deposition (CVD) with an overlayer of sputtered AlCu is discussed. The ability to deposit in-situ sequential layers without a vacuum break was a key factor in developing a technology for consistent void-free fill of sub-0.25 μm structures. This approach has resulted in a low resistivity (∼3 μΩ cm), low temperature (