Enhancement of Raman signals from low-k dielectrics with angle-resolved light scattering on nanostructure patterned Cu/low-k interconnects of IC devices

Abstract

This letter reports the enhancement of Raman signals from low-k dielectric materials in the Cu/low-k interconnects of nanoscale integrated circuit (IC) devices. The Cu nanostructure pattern of the IC device acted as an active substrate for light scattering by the surface plasmon effect, enhancing the Raman signals observed from the low-k dielectric material of the device. The enhancement of the Raman signal of the low-k material was found to be strongly dependent on the incident angle of the incident laser light. A maximally enhanced Raman intensity was achieved when this angle was approximately 45° relative to the surface normal. Our findings are significant to the characterization of low-k materials and the monitoring of low-k reliability in leading edge semiconductor technologies with nanometer-scale structures. © 2015 Author(s).