Chromium adhesion layer for copper vias in low-k technology

摘要

In integrated circuits having copper interconnect and low-k interlayer dielectrics, a problem of open circuits after heat treatment was discovered and solved by the use of a first liner layer of Cr, followed by a conformal liner layer of CVD TiN, followed in turn by a final liner layer of Ta or TaN, thus improving adhesion between the via and the underlying copper layer while maintaining low resistance.