Nanoscale Resolution Deformation Measurements at Crack Tips of Nanostructured Materials and Interface Cracks

The trend towards the application of nanoparticle filled materials in the aerospace and automotive electronics sectors have led to a strong need in material characterization on the micro and nano scale. Another challenging task is the development and evaluation of interface concepts of biological structures to microelectronic materials such as polymers, metals, ceramics and semi-conducting materials. To fulfil these needs new strategies for reliability assessment on the submicron scale are essential. Under this prerequisite Scanning Probe Microscopy (SPM) serves as the basis for the development of the nanoDAC method (nano Deformation Analysis by Correlation), which allows the determination and evaluation of 2D displacement fields based on SPM data. In-situ SPM scans of the analyzed object are carried out at different thermo-mechanical load states. The images are compared utilizing grayscale cross correlation algorithms. This allows the tracking of local image patterns of the analyzed surface structure. The derived results are full-field displacement and strain fields. Due to the application of SPM equipment deformations in nanometer range can be easily detected. The method can be performed on bulk materials, thin films and on devices i.e microelectronic components, sensors or MEMS/NEMS. Furthermore, the mechanical characterization of material interfaces can be carried out with highest precision.