UV-hardened high-modulus CVD-ULK material for 45-nm node Cu/low-k interconnects with homogeneous dielectric structures

A UV-hardened high-modulus ULK (ultra low-k) material is proposed for 45-nm-node Cu/low-k interconnects with homogeneous dielectric structures. An elastic modulus as high as 16 GPa was achieved for the ULK material with k=2.65. By combining this material with an advanced dielectric barrier (k=3.7), interconnect test devices with 65-nm-node dimensions were fabricated. The UV-hardened high-modulus ULK material is shown to be effective in improving electrical performance while maintaining sufficient mechanical integrity.