A Novel Sample Preparation Method of Four Point Bend Adhesion Test and Its Application on Cu and Low k Interfaces

摘要

A novel sample preparation method for four point bend adhesion test has been developed without traditional dicing, notching and polishing steps. The new method is believed to be reliable with good repeatability (standard deviation < 0.5). Load-displacement curves show that the new technique provides improved results. The primary benefit of this method is elimination of fracture inducing defects, which subsequently provides data with tighter distributions and increased throughput at a lower cost. Interfacial adhesion strength of both the copper barrier low k (BLOk"') and Damascene Nitride?dielectric films to the copper surface has been studied using the new method. By modifying the interface bonding environment, BLOk/copper and SiN/copper interfaces can be strengthened up to 10 J/m2. The interfacial analysis shows that such an improvement is accomplished by removing the CuO from the surface in-situ with a transition to BLOk or SiN deposition.