New metal layers for integrated circuit manufacture: experimental and modeling studies

Copper migration continues to be an important consideration in new and emerging interconnect technologies. As line dimensions shrink and new low k materials are introduced into the integrated circuit (IC) structure, the danger of electrical failure due to copper migration increases. The search for better barriers and new copper alloys that resist migration is being sought. Important considerations for copper migration are the adhesion characteristics, which add to the electrical failure phenomenon and also help determine the survivability of the metallic layers in the IC build up process. To understand the survivability issues, we have employed a combination of experimental and modeling studies to determine how the combination of metallic layers may interact. Both the experimental tests and the modeling have been found to be consistent and simple molecular models can be used to predict gross failure trends. These studies have directed us toward newer barrier and copper alloys layers that should be useful in the next Generation. (C) 2004 Elsevier B.V. All rights reserved.