Dual hardmask process for the formation of copper/low-k interconnects

摘要

The invention describes a method for forming integrated circuit interconnects using a dual hardmask dual damascene process. A first hardmask layer (50) and a second hardmask layer (60) are formed over a low k dielectric layer (40). The trench pattern is first defined by the second hardmask and via pattern is then defined by the first hardmask. Any interaction between low k dielectrics (40) and the photoresist (80) at patterning is prevented. The BARC and photoresist may be stripped before the start of the dielectric etching such that the low k dielectric material is protected by the hardmasks during resist strip.