A Study of Adhesion and Improvement of Adhesion Energy Using Hybrid Low-k (porous-PAr/ porous-SiOC(k=2.3/2.3)) Structures with Multi-layered Cu Interconnects for 45-nm Node Devices

Adhesion tests for a real Cu/low-k patterned structure were studied for 45-nm node devices. Results from 4 point-bending (4PB) and modified edge lift-off tests (m-ELT) were compared. Cu dual damascene interconnects structures with stacked hybrid low-k which is porous-poly-arylene(p-PAr)/porous-SiOC(p-SiOC) (k=2.3/2.3) were evaluated. Peel-off occurred in different locations in the real patterned structures subjected to the m-ELT test and in the structures subjected to the 4PB test. In addition, the adhesion energy (Gc: interface fracture energy) of the peeled-off interfaces was improved (Ge ges1.6x) by different treatment processes.