Adhesion studies of thin films on ultra low k

Adhesion of interfaces related to LKD 5109, a spin-on ultra low k (ULK) material, is quantified using the four-point-bending method. Processing and surface treatment are optimized. Results are compared to CMP process impact. Relatively low adhesion levels are measured for liner/ULK, ULK/cap layer and ULK/cap layer/metal layer interfaces as expected for an ULK material. Nevertheless, CMP can be performed with success on blanket wafers and on an ULK/Cu damascene structure.