Improved Metallurgy for Wiring Very Large Scale Integrated Circuits
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
Pure copper (Cu) wiring reduces resistivity by nearly a factor of two compared with conventional aluminum/copper (Al/Cu) wiring. For prevention of Cu migration below wiring levels and to provide improved contact resistance, a barrier layer of at least 100nm of zirconium (Zr) hafnium (Hf), or titanium (Ti) is applied before Cu deposition. This two- layer metallurgy system provides the desired low resistance in wiring and contacts, high electromigration resistance, and is compatible with insulating materials and processes in current use.