Ultra-low Resistance Diret~ Contact Cu Via technology Using In-situ Chemical Vapor Cleamng

Abstract

The lowest contact resistivity, 5.8-6.8~10-lQcm (0.038Wvia for 0.44ym@), was obtained with a Cu doublelevel interconnection with via plug connected without barrier metal. The double-level interconnect was fabricated by a dual damascene process using Cu-CVD. In order to achieve ultra-low resistivity, we have developed a cleaning procedure [lst: Os plasma, 2nd: Mute H F solution, 3rd: insitu hexafluoroacetylacetone (Hbfac)) vapor cleaning] after via etching. This technology reahze one order lower via resistance than conventional one.