Fragmentation testing has been used for decades to assess thin film fracture and delamination. Hooke’s law is generally used to determine a film fracture stress from the crack onset strain observed in micrographs or measured as an electrical resistance increase. While this method is in theory suitable in the elastic regime, it neglects important film characteristics, such as residual stress, microstructure, or film architecture. Thus, there is a need to improve fracture analysis using fragmentation to avoid significant errors in measuring fracture stress or apparent fracture toughness of thin films. In-situ X-ray diffraction fragmentation experiments can measure the film fracture stress even for individual layers being part of a multilayer. Which characteristics influence the apparent fracture behavior will be demonstrated on Mo thin films on polyimide. Graphical abstract: [Figure not available: see fulltext.]
Bibliographische NotizFunding Information:
Open access funding provided by Austrian Science Fund (FWF). This study was funded by Austrian Science Fund, I 4913-N.
We thank Helmholtz-Zentrum Berlin (HZB) for the allocation of neutron/synchrotron radiation beamtime and for financial support (Proposals 15101992-ST, 15202990-ST/R-1.1-P, 161224035-ST, and 192-08532-ST-1.1-P). During the experiments we were supported D.M. Többens of HZB. The work was supported the Austrian Science Fund (FWF, Project Number I 4913-N). V.L. Terziyska and K.H. Pichler from the Montanuniversität Leoben are acknowledged for deposition of the samples.
© 2023, The Author(s).