Method of improving mechanical properties of semiconductor interconnects with nanoparticles

摘要

In a BEOL process, UV radiation is used in a curing process of ultra low-k (ULK) dielectrics 100. This radiation penetrates through the ULK material and reaches the cap film underneath it. The interaction between the UV light and the film leads to a change the properties of the cap film. Of particular concern is the change in the stress state of the cap from compressive to tensile stress. This leads to a weaker dielectric-cap interface and mechanical failure of the ULK film. A layer of nanoparticles 120 is inserted between the cap 130 and the ULK film. The nanoparticles absorb the UV light before it can damage the cap film, thus maintaining the mechanical integrity of the ULK dielectric.